Midrasch zu Bamidbar 15:15

Why was the law given in the desert? To teach us that just as the desert is free to all men, so the words of the law are free to all who desire to learn them. Also, lest a man should say: “I am a student of the law that was given to me and my ancestors, while you and your ancestors are not students of the law; your ancestors were strangers”; hence it is written: An inheritance of the congregation of Jacob (Deut. 33:4). This tells us that the law was an inheritance for all who associate themselves with Jacob. Even outsiders who devote themselves to the law are equal to the high priest, as it is said: Which if a man do, he shall live by them: I am the Lord (Lev. 18:5). It does not refer to priest or Levite or Israelite but merely to man. Thus, One law and one ordinance shall be both for you and for the stranger that sojourneth with you (Num. 15:16). Observe what is written concerning the sons of Jethro: And the families of the scribes that dwelt at Jabez: the Tirathites, the Shimeathites, the Succathites (I Chron. 2:55). The name Tirathites (understood as derived from Aramaic tar’a, “gate”) indicates that they sat at the gate to the inner chamber of the Temple; Shimeathites (which includes the letters of the word shema, “hear”) implies that all the Israelites heard the law from their lips; and Succathites (which includes the word sukkah, “covered by”) suggests that they were enveloped by the Holy Spirit. Who were these? They were Kenites who came from The father of the house of Rechab (ibid.). The father-in-law of Moses was a Kenite, and Shemaiah and Abtalion and the descendants of Sisera were also Kenites. They studied the law in public like the men of the Great Synagogue. Why was that? Because the law was given to all Israel. Therefore it is written: These words that the Lord spoke unto all your assembly (Deut. 5:19).

(Bamidbar 15:15) "The congregation (— one statute shall there be for you, etc."): This (Ibid. 2, "the sons of Israel") tells one only of the men (as bringing libations). Whence do I derive (the same for) the women? From "the congregation." "One statute shall there be for you and for the stranger that sojourns (among you"): Because this speaks of Israel, the proselytes must be (specially) included. "an everlasting statute unto your generations": that this (the libations) obtain in all the generations. "As you, thus shall the stranger be before the L-rd": What is the intent of this? From (Shemot 28:38) "And it (the head-plate) shall be on his (Aaron's) forehead always for acceptance for them before the L-rd," I might think that this applied only to (native-born) Israelites. Whence do I derive (the same for) proselytes? From "As you, thus shall the stranger be before the L-rd." (Ibid. 16) "One Torah and one judgment shall there be for you and for the stranger who sojourns among you": Scripture hereby likens the proselyte to the native-born in respect to all the mitzvoth of the Torah.

(Bamidbar 15:15-17) "And the L-rd spoke to Moses, saying: … upon your coming to the land whither I bring you there": R. Yishmael says: Scripture varied (linguistically) this "coming" from all the other "comings" in the Torah. For in all the other instances it is written "And it shall be, when you come to the land"; "And it shall be when the L-rd shall bring you" (all such expressions connoting permanent settlement), whereas here it is written "upon your coming" (connoting the moment of arrival), to teach that the mitzvah of challah (the Cohein's share of the dough) devolved upon them immediately upon their entering the land "whither I bring you there": From here you derive that produce grown outside the land which enters the land is subject to challah. It is from here (Eretz Yisrael) to there that R. Eliezer ruled it subject to challah, and R. Akiva exempts it. R. Yehudah says: Produce grown outside the land which entered the land — R. Eliezer exempts it, it being written (Ibid. 19) "and it shall be, when you eat of the bread of the land," and R. Akiva rules it subject to challah, it being written "there" (i.e., in Eretz Yisrael). What is the intent of "when you eat of the bread of the land"? From (Ibid 20) "the first of your dough," I would understand even other produce (as being subject to challah). You, therefore, reason: It is written here "bread" and elsewhere (Devarim 16:3) "bread." Just as "bread" there is of the five species: wheat, barley, rye, oats, and spelt, so, "bread" here. (Bamidbar, Ibid. 19) "that you shall separate an offering (terumah)": This speaks of the "great terumah" (taken from one's produce [viz. Devarim 18:4]) — But perhaps it speaks of the challah offering! — (This cannot be, for) (Bamidbar, Ibid. 20) "challah, you shall offer up an offering" already speaks of challah. How, then, is "you shall offer up an offering to the L-rd to be understood? As referring to the "great terumah," (which is taken before the challah is separated). (Devarim 18:4) "The first of your corn, your wine, and your oil … shall you give to him" (the Cohein). This is mandatory. You say that it is mandatory, but perhaps it is optional (i.e., if you separate it, you must give it to him, but you need not separate it.) It is, therefore, written "You shall separate terumah" — It is mandatory and not optional. I might think that flours, too, are subject to challah; it is, therefore, written "the first of your dough" — when it has become dough. [From here they ruled: One may eat a chance meal of started dough of wheat before it has been rolled out, or of barley before it had been well kneaded, (after which it becomes subject to challah). If one ate of it — of wheat flour, after it had been rolled out, or of barley flour after it had been well kneaded, (without taking challah) — he is liable to the death penalty. Once she had added the water, she must remove her challah, so long as there not remain there (in the kneading-trough) five quarter-kavs or more of flour that had not been mixed with water, (for if there did, they are subject to challah.)] For challah is not taken from (unprocessed) flour. If one had not taken challah from the dough, I might think he may not take it from the bread; it is, therefore, written (Bamidbar, Ibid. 19) "And it shall be when you eat of the bread of the land, you shall separate, etc." R. Akiva says: All (vis-à-vis the separation of challah) is contingent upon its forming a crust in the oven. (Ibid. 24) "As terumah of the threshing floor, so shall you offer it" (the challah). Just as with terumah, (the designated separation is) one (part) to a thousand, so, challah. And just as terumah of the threshing floor is "raised" (if it became intermixed) with one hundred and one times (its amount of non-terumah — which may then be eaten by non-Cohanim); and it creates a forbidden admixture for non-Cohanim if it fell into (only) a hundred of non-terumah; and it creates liability to the death penalty and to the one-fifth (chomesh) restitution penalty (viz. Vayikra 5:16) — so, with challah. These are the words of R. Yoshiyah. R. Yonathan "whispered" to him: You liken it to terumah of the threshing floor, (the percentage of) which is unspecified (in the Torah)? I will liken it to terumath ma'aser (Bamidbar 18:26), (the percentage of) which is explicit (in the Torah) — and one-tenth should be taken (as challah). He responded: It is written "As the terumah of the threshing floor, so shall you offer it." It is likened to terumah of the threshing floor, and not to terumath ma'aser.