Deuteronómio 31:19 Midrash: Mekhilta DeRabbi Yishmael, Ein Yaakov (Glick Edition), Bamidbar Rabbah & Sifrei Bamidbar

R. Akiva says: What is the intent of "And these are the judgments"? From (Leviticus 1:2) "Speak to the children of Israel and say to them," I would think, only once. Whence do I derive that it is to be repeated two, three, and four times until it is assimilated? From (Devarim 31:19) "and teach it to the children of Israel." I might think that it is to be taught but not repeated. It is, therefore, written (Ibid.) "Place it in their mouths." I might think that it is to be repeated (even) if it is not understood. It is, therefore, written "And these are the judgments." Set them out before them as a set table, as it is written (Ibid. 4:35) "You have been shown to know, etc."

GEMARA: Rabba said: "Even if his ancestors left one a scroll, nevertlieless it is a meritorious act for him to write the Holy Scrolls at his own expense, as it is said (Deut. 31, 19) Now, therefore, write this song." Abaye objected [from our Mishnah]: "He shall write the Holy Scrolls for himself," and must not be satisfied with those of his parents. And this speaks only of a king, but not of an ordinary man. Our Mishnah treats of two Holy Scrolls, as we are taught in the following Baraitha (Ib. 17, 18) He shall write for himself a copy of this law — i.e., He must write for himself two Holy Scrolls, one which he must carry wherever he goes, and one which shall remain in his treasury. The one he has to bear with him he shall write in the form of an amulet, and place it on his arm, as it is said (Ps. 16, 8) I have always set the Lord before me. However, he must not enter a bath or a toilet with it, as it is said (Ib., ib. 19) And it shall be with him and he shall read; i.e., it shall be with him in those places where it is permitted to be read, but not in those places where it is not permitted.

(Fol. 38.) R. Chama b. Chanina said: "Moses became rich of nothing else than from the chips of the tablets, as it is said (Ex. 34, 1) Hew thee out; i.e., their chips be thine." R. Josa b. Chanina said: "In the very beginning the Torah was given to no one except to Moses and his children, as it is said (Ib. 27) Write thee down and hew thee down; i.e., just us the chips be thine so also shall the writing (the Torah) be yours. Moses, however, was liberal with the Law and gave it to Israel. Concerning him the passage reads (Pr. 22, 9) A man of a benevolent eye will indeed be blessed, for he giveth of his bread to the poor." Raba raised the following objection (Deut. 4, 14) And me did the Lord command at that time to teach you, statutes and ordinances. Hence it shows that the Torah was given unto Israel. This means, He commanded me, and I gave it to you. But again it is written (Ib. 5) See I have taught you statutes and ordinances, just as the Lord my God commanded me. This also means as the Lord commanded me and I taught to you. But again it is written (Ib. 31, 19) Now therefore write ye for yourselves this song, (hence it was given unto Israel). This refers merely to the song he gave. But again it is written in the same passage. In order that the song may become a witness against Me for the children of Israel, hence it was given to the children of Israel? We must therefore say R. Chisda's tradition refers merely to the argumentive deductions.