出エジプト記 18:13

ויהי ממחרת AND IT CAME TO PASS ON THE MORROW — This was really the day after the Day of Atonement: so have we learnt in Siphré (Mekhilta). Since the Day of Atonement is not mentioned anywhere in this section that deals with the Giving of the Law what is the force of ממחרת? i. e. in relation to what particular day in the history of the Law-giving is the term ממחרת, “on the morrow”, used? It means the morrow after he (Moses) descended from the Mount Sinai, and you must admit that it is impossible to say that this was any other day but the morrow after the Day of Atonement because, before the giving of the Torah, one could not say, (v. 16) “and I do make them know the statutes [of God and His laws]” (which are part of the Torah), and from the day when the Torah was given until the Day of Atonement Moses did not sit down to judge the people, since immediately after the Torah was given he ascended the mountain and descended only on the seventeenth of Tammuz when he broke the tablets in pieces. On the next day he again ascended the mountain early in the morning and stayed there eighty days, descending on the Day of Atonement (cf. Tanchuma כי תשא, Rashi on 33:11, Deuteronomy 9:18 and 10:1). Consequently this section is not written (placed) in its chronological order, for this paragraph commencing with ויהי ממחרת and ending with “Moses let his father-in-law go and he (Jethro) went his way into his own land” was not said before the second year after the Exodus. For even according to the view of one who says that Jethro came to Moses before the giving of the Torah (Avodah Zarah 24a) his dismissal into his own land did not take place until the second year, for it is stated here (v. 27) “Moses let his father-in-law go”, and we find in the account of Israel’s journey through the wilderness beneath their banners (which according to Numbers 10:11 began in the second year) that Moses said to him, (Numbers 10:29, 31) “We are journeying etc…. Forsake us not, I pray thee”. Now if this incident happened before the giving of the Torah (including Jethro’s departure) where do we find it related that he returned after he had let him go and he had taken departure? And if you object that there (in the section in Numbers which Rashi has quoted as evidence that Jethro’s departure took place in the second year) it does not mention Jethro at all but Hobab, and that the latter was not Jethro but the son of Jethro, then I reply that Hobab is identical with Jethro and not his son, because it is written, (Judges 4:11) “of the sons of Hobab, the father-in-law of Moses”. וישב משה וגו׳ ויעמד העם MOSES SAT … AND THE PEOPLE STOOD He was sitting like a king and they all stood, and the thing was distasteful to Jethro in that he made light of the respect due to Israel. He therefore reproved him for this, as it is said (v. 14) “Why sittest thou only” — and they all stand! (Mekhilta) מן הבקר עד הערב FROM MORNING UNTO EVENING — Is it really possible to say so — that Moses sat the whole day long? But the explanation is that any judge who gives a rightful decision as truth demands it, even though he spends but one hour on it, Scripture accounts it to him as though he had occupied himself with the Torah the whole day long, and as though he became co-partner with the Holy One, blessed be He, in the work of the Creation of which it is stated, “It was evening and it was morning” (cf. Mekhilta; Shabbat 10a).

וַֽיְהִי֙ מִֽמׇּחֳרָ֔ת וַיֵּ֥שֶׁב מֹשֶׁ֖ה לִשְׁפֹּ֣ט אֶת־הָעָ֑ם וַיַּעֲמֹ֤ד הָעָם֙ עַל־מֹשֶׁ֔ה מִן־הַבֹּ֖קֶר עַד־הָעָֽרֶב׃

And it came to pass on the morrow, that Moshe sat to judge the people: and the people stood by Moshe from the morning to the evening.