Rambam Laws of Shabbat Chapter 4 – Hatmanah (Insulation)

With God’s help, Rambam Laws of Shabbat Chapter 4.

We are holding in the middle of Laws of Shabbat, we are now going to learn the fourth chapter, hatmanah. In the previous chapter we learned about placing things on the fire on erev Shabbat, or returning them on Shabbat. Now we are going to learn when there is no fire involved, but rather one covers the food in merchandise or things that keep warm, the laws of what is permitted and what is forbidden.

And we must mention the sponsor of our shiur, the supporter of Torah, our friend the Rabbi R’ Yoel Halevi, who supports us so that we can produce the flour for the Torah. From him they will learn and so they will do.

Law 1: Davar HaMosif Hevel and Davar She’eino Mosif Hevel

The Rambam’s Words: Two Categories of Materials

The Rambam says, “There are things”, there are certain types of things… so the Rambam is going to tell us here what one may store in, it’s called hatmanah, storing the food. That is, on erev Shabbat there is another method. The previous method was that it should be on the fire on Shabbat. The other method is that you cook on erev Shabbat, and on Shabbat one should only store it in something that holds the warmth.

We see here in both chapters that there is a concept of having hot food on Shabbat. The Rambam didn’t say it clearly, but in the Shulchan Aruch… I mean the Rema says that there is a concept, the Rema goes like this, that there is a concept to eat a warm, hot food on Shabbat. We try, it’s not a lawless world, we don’t do many things we don’t do because of lest he stoke, but we calculate all the laws because it’s an important thing, it’s not just anything.

Yes, it could be that the Rambam meant that we saw the previous chapter, and we’re in the middle of saying that it’s permitted, there are only prohibitions because of lest he stoke, perhaps that’s what he’s emphasizing. I hear.

The Rambam says, “There are things”, there are certain types of things, “that if one insulates food in them”, if one places in them a warm dish, “they heat up and add to its cooking”, these things make the food become even warmer, and it helps to cook it, it adds cooking. Anyway, these things have heat almost like fire. Such as geft, waste from olives, manure, salt, sid. Sid is not paint, whatever, some kind of sand from which one usually makes lime. Etc., or sand, or zagin, I think it’s the shells, zagin chartzanim vezag, yes, it’s the shells from grapes, or mochtin is usually cotton, small pieces, and herbs, or grass, when they are moist from themselves, on these three things, zagin, mochtin, and herbs, if they are wet. All these things have a nature that they make things that are stored in them hotter.

And how are they called in the Gemara? The Rambam says, “And these things are called”, they are called in the… when one learns these things they are called “davar hamosif”, a thing that adds, that makes more heat.

But now he says, there are types of things that if one stores a dish in them “it holds the heat”, there are things that have the quality that they can keep warm, but they cannot make warmer. “And they don’t add to its cooking”, it doesn’t make it hotter, it only makes the food stay hot. That is, “they prevent it from cooling”, it only protects from becoming colder, it holds it. Such as zagin and mochtin and herbs, the three things that he enumerated, but “dry”, that are already dry. Or the other things are garments, merchandise, fruits, bird wings – feathers from a bird, ne’oret hapishtan – small pieces of waste, small pieces from flax, or sawdust from carpenters – small pieces of wood, and shelulin and gizei tzemer – two types of hide or skin from an animal.

All these things are also things that are good to store a dish in, but only to keep hot. This is called in the language of the Sages “davar she’eino mosif”, a thing that doesn’t add heat. The Gemara calls it “mosif hevel” or “eino mosif hevel”. The Rambam only says “mosif”.

Novel Point: “Davar HaMosif” Doesn’t Mean Literally That It Gets Hotter

Yes, I think one must understand, because I’ve seen people talk about this, I don’t remember what their final conclusion in it is, but simply it’s not possible that a thing that is not itself hot should make another thing hotter. That’s not the way reality works. Take the best thermos, the best insulation, put in it a hot soup, it stays very hot, but it doesn’t become hotter.

Apparently one must learn that when the Sages say davar hamosif, they mean like we have a good thermos, it holds it as if, let’s say, very hot, or it doesn’t become hotter than before. Or perhaps one mosif means that it keeps it not cold, not that it keeps it as hot as it was, or something like that, almost as hot. Because it’s very hard to believe that davar hamosif is literally that it becomes hotter.

I hear that there are those who will argue, and it makes some… there is some way that one can find some grass that should make hot, but it’s hard to believe that this is what we’re talking about in hatmanah.

Law 1 (Continued): The Law of Hatmanah in Davar HaMosif – A Rabbinic Decree

The Rambam’s Words: A Decree Lest He Boil and Return and Cover on Shabbat

Now, first of all the Rambam says a fact, right? Like a Mishnah. The Rambam says like this, apparently, just like that, from what we’ve learned until now, apparently there wouldn’t have been any problem in both of them, because there is no prohibition of cooking, and there is no fire. The Rambam says like this, according to the law it should have been, and it was, so originally the law was like this, that one may insulate even in davar hamosif hevel. If one wants to place a hot pot on erev Shabbat so that it should stay hot, one should be permitted to insulate from erev Shabbat even in a davar hamosif, even in the thing that adds or holds very strongly the heat, mosif hevel. “And the dish that is insulated should remain on Shabbat, and the dish should remain there on Shabbat, like on the fire on Shabbat”, I see here even a way that one may return to the fire, “a davar hamosif cannot be worse”.

But in practice, the Sages forbade insulating in davar hamosif hevel, the Sages did forbid insulating in the davar hamosif, even if one places it on erev Shabbat. Why? The decree is like this, we are afraid, because the thing is mosif hevel, “lest the dish boil on Shabbat”, the pot becomes very hot, and he’s afraid that it shouldn’t be too hot, he will temporarily remove the cover, he needs to uncover it a bit, in order to calm its boiling, so that it should ease a bit from the heat, and only afterwards and he will return and cover on Shabbat he will go cover it on Shabbat.

What is the problem then? When we say like this it comes out that he is insulating in davar hamosif on Shabbat, when he puts it back, he is again covering, he is then insulating in davar hamosif on Shabbat, and this is forbidden. Why exactly is this forbidden we also don’t yet know.

Discussion: Why Is Hatmanah in Davar HaMosif on Shabbat Itself Forbidden?

The Rambam in Perush HaMishnayot that stands in siman 3 says that the decree lest he insulate, must have the same decree lest he insulate in hot ashes. He brings that in Perush HaMishnayot it says something else, that if in the middle of Shabbat it can be too similar to cooking, or it looks itself like cooking, or as others say, so it says in the Shlomo and other places, or he says that the Rambam says that he came to heat on Shabbat, he will place it on the fire, on the fire one may not place on Shabbat, even though even a thing that is fully cooked, it looks too similar to cooking, and if he goes to open on Shabbat and put back, he came to place on the pot also something, on the fire also something, it will warm up more, so he brings, it’s also a bit unclear.

Question: He Wants It Not To Be So Hot – Why Will He Place It on the Fire?

Why then, he wants it not to be so hot, he opened it in order to calm its boiling.

Yes, but perhaps the calming from boiling is not the same as it being cold, perhaps this is something else. Do you understand like this? One cannot say the same detail, perhaps it’s cooking, perhaps it’s bubbling, he doesn’t want it to bubble, perhaps it’s bubbling over, so he warms himself afterwards. He needs to make sure it’s the right temperature. It can be two different things.

The point is hatmanah on Shabbat we certainly don’t know, therefore a davar hamosif, since it can cause that one should need to insulate on Shabbat, is also forbidden.

Law 1 (Continued): Hatmanah During Bein Hashemashot in Davar HaMosif

The Rambam’s Words: Permission During Bein Hashemashot

Therefore, it is permitted to insulate in davar hamosif during bein hashemashot. During bein hashemashot one may insulate in davar hamosif hevel. It’s not while it’s still day, but when it’s already becoming Shabbat.

Right.

And during bein hashemashot one may do hatmanah in davar hamosif hevel. Why is the reason? Because during bein hashemashot they have already boiled and calmed from while it was still day, they have already eased from the heat, therefore there is no longer the concern of he will need to uncover, since they have calmed from being boiling, therefore it won’t become so strongly hot anymore, there is no longer the concern of lest he need to uncover, the whole thing.

Discussion: Bein Hashemashot Is Easier Than Erev Shabbat

Speaker 1: Which is an interesting thing, because bein hashemashot, it seems bein hashemashot is a time when one may still do melachot.

Speaker 2: Rabbinic melachot.

Speaker 1: With rabbinic. It’s only a rabbinic prohibition hatmanah.

Speaker 2: But the whole question is lest he boil and return on Shabbat.

Speaker 1: Mm.

Speaker 2: It’s also only a rabbinic prohibition.

Speaker 1: Mm.

Speaker 2: Hatmanah is not a prohibition, it’s not cooking, cooking.

Speaker 1: No, but it’s interesting that bein hashemashot is even easier than on erev Shabbat, yes, because there isn’t the decree, yes.

Right. And here it also seems clear that he doesn’t say even a boiling pot is permitted. Permitted we learn because it’s already just a boiling pot, it’s interesting, they have already boiled.

We’re talking about, well, necessarily, if someone has a pot that is coming down from the stove, perhaps he may not, but during bein hashemashot he may, because a person doesn’t cook before Shabbat right during bein hashemashot, he cooks an hour earlier, and now he only wants to insulate so that it should be warm for the meal.

Proof That “Davar HaMosif” Doesn’t Mean Literally Hotter

And here you also see clearly that davar hamosif doesn’t mean that it becomes literally hotter, but that it can become boiling.

Speaker 2: But if that were the word, he would have said because then it’s not called mosif hevel. If like you say, because then itself it’s already not mosif hevel.

Speaker 1: It’s already not a davar hamosif. He doesn’t say like this, he says because it’s just because, they have already boiled and calmed.

Speaker 2: But one should have said that all these things that were said mosif is only when one places in a pot when it’s very hot it is mosif. When one places in a pot when it’s not very hot it’s not mosif hevel, it can no longer, it no longer has the power.

Speaker 1: I didn’t understand what we’re talking about. I’m just saying that I argued that davar hamosif doesn’t mean that it becomes literally hotter. If it were literally hotter, “since they have calmed from being boiling” wouldn’t be correct, because it can still become davar hamosif. Does this make hotter? The answer is no, it makes it stay very hot, but it doesn’t make hotter.

I didn’t understand what you answered, I still didn’t understand what you meant. I understand like this, that the davar hamosif is good enough that when you place a very hot pot, that it doesn’t keep strongly hot, but when you place not a hot pot,

Law 2: Hatmanah in Davar She’eino Mosif – On Shabbat Itself

I hold that there is a distinction. I don’t agree. I hold that there is a distinction. But then this is permitted. I mean, on erev Shabbat one may even lechatchilah.

The Rambam says further, “And likewise, according to the law it should have been permitted to insulate a dish in davar she’eino mosif on Shabbat itself”. According to the law one should have been permitted, there is no reason why one shouldn’t be allowed to insulate on Shabbat. It’s not cooking and it’s nothing. We’re talking about a davar she’eino mosif, there isn’t even a concern, it doesn’t look like cooking or what.

“But even this thing the Sages forbade to insulate on Shabbat”. Why? “A decree lest he insulate in hot ashes”. There is another way of insulating in hot ashes. Hot ashes means just a mixture of coals with fire, and there are sparks of fire in it. Then, if he insulates in hot ashes on Shabbat, this is raking the coals, this is close to being kindling. So, every thing that is, every insulating we are afraid lest he insulate in hot ashes. Even davar she’eino mosif, even on Shabbat, even she’eino mosif one may not. Why? Because he will then insulate in hot ashes, and then he is actually raking the coals.

Okay.

Doubtful Darkness

Not clear. And also, another thing, sorry, until here. The Rambam says, doubtful darkness or not darkness, when it’s a doubt if it’s already Shabbat. What may one do then and what not? It’s like this, it is permitted to insulate the hot thing. Then one may. Then there is not yet the prohibition of lest he boil, then there is still, one may still insulate in a hot thing.

We already learned this actually, that during bein hashemashot, because it’s not just pots during bein hashemashot that are boiling, this is not that. This is when during bein hashemashot, now he’s talking about a doubt. A doubt that it’s already actually night. Bein hashemashot is when he knows for sure that it’s bein hashemashot. A person doesn’t know, it could be that it’s already actually night. Then it is permitted. There is already a… in doubts it’s permitted, the prohibition of… this is a weaker prohibition.

Okay.

Insulating a Cold Thing on Shabbat

What may one do on Shabbat? On Shabbat itself, a thing that is not hot at all, it is permitted to insulate the cold thing on Shabbat in davar she’eino mosif. Why does he want to insulate it? So that it shouldn’t become too cold, or so that its coldness shouldn’t dissipate, so that it shouldn’t be so cold, or so that it shouldn’t become colder. One may. A cold thing, that its coldness shouldn’t dissipate means even to warm up a bit. A cold thing one may insulate on Shabbat. He doesn’t say hot and a bit hot, actually cold, like whatever, not hot at all. Permitted.

Hot Water That Was Uncovered, Changing Covering, and Transferring to a Second Vessel

Another thing, sorry, hot water that one insulated on erev Shabbat and was uncovered on Shabbat, it opened, the insulation didn’t hold, it is permitted to cover them. One may fix the insulation. It’s not she’eino mosif. He doesn’t add any new insulation, he goes the same insulation that he had, he fixes it. This is not a problem.

Right. And it is permitted to cover, what happens to the covering, the thing that one places on the pot? It is permitted to cover the covering on Shabbat. One may on Shabbat change the thing over the pot. How? He takes off the coverings, he may remove what was covered with coverings, and lift the pot there is still another covering. May one remove that and place a vessel on top of a vessel and put other merchandise? A vessel on top of a vessel is the thing that we talked about earlier, one of the things has a… one mosif hevel.

Yes.

Yes. So one may change. But not a vessel on top of a vessel, but rather place a covering. May change from one davar hamosif, one mosif, from the other davar she’eino mosif. What… what is already one mosif. What is not mosif. Already.

Transferring the dish and in it hot water from a vessel to another vessel. Until now we’re talking that he takes the pot that was on the fire and he wants to now insulate it. But if one takes a fresh pot and pours in the dish from the first vessel, from the pot that was on the fire, the second vessel one may already insulate on Shabbat. One may, on this there is not the prohibition.

Law 3: Placing a Kettle on Top of a Kettle

Next law. The Rambam says like this, what happens regarding not placing things directly on fire, but like this: One may place a kettle on top of a kettle on Shabbat. One may place a pot on a warm pot on Shabbat. Or kettle usually means a teapot for water. A pot is a pot for dishes, for solid things. One may place a kettle on top of a kettle, a pot on top of a pot, or a pot on top of a kettle, a kettle on top of a pot. And in their mouths are stoppers, one may even… stop up the upper kettle… the upper kettle or one means to say that both we’re talking with a stopper. What exactly? One may even place with the spout stopped. Not so that they should be heated, not that the upper pot should now become hot, but so that their heat should remain, but so that the heat should be maintained.

Why? Ah, you’re saying also that it’s like a davar hamosif hevel, the lower pot makes hotter the upper pot. But they only forbade insulating on Shabbat. The prohibition that the Sages said in hatmanah is only when one insulates, when one takes completely around a pot. But to place a hot vessel on top of a hot vessel so that its heat should remain, is permitted, so that it should stay warm is permitted. The distinction is whether he places it in, it’s surrounded by… hatmanah means when the pot is completely surrounded from all four sides, or the word is because it’s lying on something. In short, when it’s not called hatmanah one may.

A Cold Vessel on Top of a Hot Vessel

But one may not place a vessel containing something cold on top of a hot vessel on Shabbos. This is not permitted. That is, one may not place a pot that contains cold things that are completely cold on top of a hot pot on Shabbos, for he thereby generates heat in it on Shabbos. Through this he causes the upper pot to become warm.

What is the prohibition? Is the prohibition molid (generating something new), or is it mechazi k’mevashel (appearing like cooking), or is it a concern of mevashel (cooking)? For he generates heat in it. Does he mean that it’s a prohibition of being molid, or does he mean that it becomes hot? And we are stringent that it’s a concern of mevashel.

What? So it says here, I don’t know. So it says here, no?

Yes, but he doesn’t say, he says molid chom (generating heat), he doesn’t say what that means, what the problem is with this molid chom.

And one may place on erev… The commentators say that it can become actually hot, usually it doesn’t become actually hot, but it can become actually hot, and then there will be actual cooking. There are others who say differently, it’s not clear.

But if he placed it on erev, if one placed a vessel containing something cold on top of a hot vessel on Shabbos, on erev, before erev Shabbos, then yes it is permitted. Because this is only like hatmanah (insulation) with something that adds heat, which one also may not do on erev Shabbos. But again, because this is not hatmanah, this is only placed next to the pot, it’s not called hatmanah, as we learned earlier, al gabei (on top of) is not called hatmanah, so it is permitted.

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That’s the answer in chapter 4 in the laws of hatmanah, very quickly.

Do you sometimes do hatmanah?

I don’t do it so much. But a crock-pot warmer yes. There are people who hold that a crock-pot is hatmanah b’davar hamosif hevel (insulation with something that adds heat).

Okay.