I'm learning laws of salting in the Shulchan Aruch. One concept I'm battling to understand is "דם שפירש ממקום למקום" - blood that moved from one place to another. Here's a good example of my confusion: see YD 69:18. The Shach in ע"ד says that blood in the flesh that did not move is permitted, but that's only "if it didn't move at all from its place". A simple reading of this seems to imply that the Shach (and most other Rishonim and Acharonim) did not understand the concept of a circulatory system, since they seem to have a concept of a fixed place where each drop of blood belongs, and where it is permitted to eat it - but as soon as that blood moves out of its place, it becomes prohibited.

Perhaps the Mechaber disagrees with this interpretation of דם שפירש ממקום למקום, applying it only to blood the moved between two separate pieces of meat, or at least that exited this piece of meat and was later re-absorbed? In the argument over whether salting is supposed to remove all the blood or most of the blood, the Rambam comes down on the latter side, which is why he requires chalita, to seal the blood in so that it doesn't leak out when you later cook it. If that's the case, then he surely cannot agree with the way the Shach understands it, because whatever blood didn't come out with the salting has surely "moved" during the process - yet the Rambam permits it!

How do you understand this concept? And if, indeed, it is based on a misconception of the circulatory system, how would the halacha be affected?

  • This bugs you, but you accept that Chalita "seals" the blood in?
    – Double AA
    Commented Dec 19, 2012 at 14:17
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    IAE I don't really follow your problem. He's talking about Dam Eivarim not the blood in the circulatory system (which, incidentally, is hard to imagine they didn't know about; they knew about the heart). It's quite reasonable to say the the blood in the capillaries (which are tiny!) doesn't move after the heart starts pumping.
    – Double AA
    Commented Dec 19, 2012 at 14:32
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    @DoubleAA - I didn't make any judgments about chalita; I'm learning about melicha now. It's quite possible that when I get there, I'll raise another question about chalita, as you say... :)
    – Shaul Behr
    Commented Dec 19, 2012 at 14:46
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    The logic in general it seems is that blood is only assur as a cheftza of blood, but not where it is batel to the meat. Once it is poresh, it attains its issur and then doesn't lose it when it is reabsorbed.
    – Double AA
    Commented Dec 19, 2012 at 15:05
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    some sources: dafyomi.co.il/menachos/halachah/mn-hl-100.htm
    – Menachem
    Commented Dec 20, 2012 at 20:48

1 Answer 1


Read here for an evolution of the different opinions in Halacha regarding blood that moved, and eating raw meat (from the Talmud to the Poskim).

"blood that moved" is talking about the blood that is found in the meat, not the veins/arteries (as the Tur (67) and others say, while raw meat may be permitted without salting, the blood found in the veins/arteries are forbidden).

The language used by the Tur (and others), "שנתעורר לצאת‏" - That was awakened to move -, seems to indicate that it is only called "blood that moved" if it was caused to move by an outside source.

There are opinions that it is only called 'blood that moved' if it left the meat and was later reabsorbed, but I don't think we rule that way halachically.

See here for a discussion of this concept as well, by HaRav Avraham Wilhelm (I didn't read the whole thing but he brings and discusses the different opinions)

  • Per science, blood is always in the circulatory system, just in narrow and narrower tubes.
    – Double AA
    Commented Dec 25, 2012 at 18:43
  • Since the question is specifically about science, I'm going to press you further. What do you mean veins? Is that to exclude arteries? If so, why? If not, then wouldn't all capillaries fit in as well? Blood is always in a vein, artery or capillarity (when not inside the heart/lungs/liver/kidney). What does 'in the meat' mean scientifically?
    – Double AA
    Commented Dec 25, 2012 at 18:51
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    @DoubleAA: The term the Tur uses is 'the strings that have blood in them, since the blood in the strings are as if gathered and standing in a vessel'. If I had to guess, I'd say that all the tubes (veins, arteries) that are still recognizable as such are forbidden, but ones that do not have recognizable tubes are permitted. According to wikipedia en.wikipedia.org/wiki/Capillary the walls of the capillaries are just one cell thick. Hardly recognizable as tubes.
    – Menachem
    Commented Dec 25, 2012 at 19:01
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    For the record, the Rosh defines "blood that moved" specifically as having left the meat altogether; he seems to be your primary source for your paragraph beginning "There are opinions..."
    – Shaul Behr
    Commented Dec 25, 2012 at 19:36

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