Les Nombres 11:8 Halakha : Shulchan Shel Arba & Peninei Halakhah, Kashrut

A second blessing “Ha-motzi’ lehem min ha-aretz” is from the words of the scribes, which they derived a fortiori: “If one who has satisfied his hunger says a blessing, how much the more so ought one when he is hungry say a blessing.”⁵⁸B. Berakhot 35a. The explanation is that when one has satisfied his hunger and has already enjoyed the holy things of Heaven, which until he has said a blessing are prohibited to him as if they were hekdesh, how much the more so when he is hungry and about to enjoy the holy things of Heaven ought he say a blessing before eating them, so as not to be penalized with having to make a sacrilege offering (korban me’ilah).⁵⁹That is, the offering required for someone who has “stolen” the sacred food set aside for the priests. You would think that one should say “min ha-adamah” – “from the ground” in this blessing, but it gets the expression from Scripture: “le-hotzi’ lehem min ha-‘aretz.”⁶⁰Ps. 104:14: “to get food out of the earth.” Though ‘adamah and ‘eretz can both mean “earth,” ‘adamah is the term more commonly used when speaking about harvesting food grown in a field. And if you take issue with the precise meaning of the expression “lehem” – “bread,” you will find that it means food in general, as in “he [King Belshazzar] gave a great banquet [lehem],⁶¹Daniel 5:1 (JSB) translating the Aramaic “’avad lehem rav.” since the bread itself is not what comes forth from the earth, but rather the produce from which they make bread. And so you will find with the manna: “I will rain down bread [lehem] for you from the sky.”⁶²Ex. 16:4. It is well known that bread did not come down from the sky, but the manna out of which they made bread,” as it is said, “they would make it into cakes.”⁶³Nu. 11:8.

The dough for which there is an obligation of [separating] hallah is the dough that the generation of the desert was accustomed to making, as it is stated (Numbers 15:20), "The first of your kneading troughs, challah, you should separate [as] tithe." The "kneading trough" is the dough that they would prepare from the manna that fell in the desert every day for each man, as it is stated (Exodus 16:16), "This is what the Lord has commanded: Each man shall gather his requirement of food; an omer per person, according to the number of your people, shall each man take for those in his tent." They would grind the manna and make it into a dough (Numbers 11:8). And the quantity for each person was a tenth of an ephah, as it is stated (Exodus 16:36), "And the omer is a tenth of an ephah" (Eruvin 83b). But dough that is of a smaller quantity than this is not significant, so it is exempt from challah.