On the first day of the third month it was spoken, will St. Augustine (at the cited places) and Abulensis (q. 10, ch. 19). But these are now not to be heard by us, because (q. 6) we perceived [that] on that day they had not yet entered upon this journey, but only on the third day. Others, then, think God spoke these things to Moses on that very third day — as R. Moses [Maimonides] and Ibn Ezra. But these ought not to say what they nevertheless [do] say: that on that first day of the month…
(col. 114)
…the Israelites came hither, and [that] Moses twice ascended Mount Sinai and twice descended from it. For when he had ascended on that first day, and ought only [himself] to report to the Lord whether the people were willing and glad in receiving the Law — to what end would he have deferred the ascent and the answer to the third day? Had not the people at once said, “All that the Lord hath spoken, we will do”? Was Moses so slow and sluggish that he did not ascend even on the second day? There are others to whom these things seem rather said on the fourth day — as Cajetan, R. Solomon [Rashi], Lyranus, [and] Bellarmine. But since Cajetan gives the first day of the month both to the arrival into that wilderness and to Moses’s first ascent, he makes Moses far more dilatory than the Rabbis just now disapproved. The rest indeed refer this Sinaitic arrival to the third day of the month, as [was] seen above, but reckon it cannot be that on the same day Moses fixed his tabernacle, at once ascended that highest mountain, thence descended to the people to explain the divine will, ascended again to report the people’s answer, and afterward descended once more to bid all be ready against the third day. And with these I cannot agree. For, [I] consider, first, that although between Rephidim (whence they had set out) and Sinai (whither they had come) the journey was not much, yet there was so great a multitude of men that all seem scarcely to have come to that place before noon, and there to have halted. For the camp was moved thence not by night, but by daylight. Then, what an occupation for all in pitching the tents! Grant [that] Moses had Joshua, or others, to whom he might commit the erection of his tabernacle, and, freed by them from that occupation, might ascend the mount — how yet, on the same day, could he twice ascend that loftiest and most difficult mountain, twice hear the divine voices, twice descend, [and] twice summon the elders of the people? By this last way, in short, all the [things] the text hands down agree better. For (v. 10) it is said: “Sanctify them today and tomorrow, and let them be ready against the third day.” That “Today” signifies the day on which the Lord was speaking these things, [and] is to be included in that triad of days; and [that] the third day of the same triad was the very [day] on which the Lord came down to give the Law, the following [words] judge (v. 11): “For on the third day the Lord will come down.” So that, if these things were spoken on the third day of the month, it would have to be concluded [that] the Law was given on the fifth day of the same month. But those with whom I now have the dispute will have [it] given on the sixth — and this will be confirmed below. It is therefore to be settled [that] the Lord commanded these things on the fourth day of the third month, and the 48th from the Egyptian departure.