מדרש אויף שמות 19:11

1) (Vayikra 9:1) ("And it was on the eighth day that Moses called to Aaron and to his sons and to the elders of Israel"): This is one of the verses that needs expounding: It is written here: "And it was on the eighth day," and elsewhere (Shemoth 19:16): "and it was on the third day." We do not know whether (this refers to) the third day of the month (Sivan) or the third day of the number (of days of separation, viz. Shemoth 19:15). Its being written (Shemoth 19:11): "… for on the third day the L–rd will go down before the eyes of all the people on Mount Sinai" and then "And it was on the third day, when it was morning etc." tells us that it is the third day of the number, and not of the month, that is being referred to. Here, too, it is written: And it was on the eighth day," and we do not know whether it is the eighth day of the number (of days of miluim [i.e., the first of Nissan]) or the eighth day of the month (of Nissan). Its being written (Vayikra 8:33): "For seven days shall He invest your hands" tells us that it is the eighth day of the number and not the eighth day of the month. That day (the first of Nissan) took ten crowns: It was first for creation of the universe; first for the (sacrificial service of the) nesi'im (the chiefs of the tribes); first for the (sacrificial service of the) Cohanim, (that service having previously been performed by the first-born, and, on the seven days of miluim, by Moses); first for the (sacrificial) service (of the daily offerings [temidim] and all of the communal offerings); first for the descent of fire (upon the altar from Heaven); first for shechitah in the north (of the altar); first for the prohibition of bamoth (temporary altars); first for roshei chodoshim (the beginnings of months); first for the reposing of the shechinah in Israel; first for the (priestly) blessing of Israel.

Variantly: They said: We want to see our King. There is no comparing hearing to seeing, viz. (Ibid. 11) "for on the third day the L–rd will go down before the eyes of all the people on Mount Sinai."

(Exodus 19:10) "And the L–rd said to Moses: Go to the people and make them ready today" — the fourth day — "and tomorrow" — the fifth day. (Ibid. 11) "And have them be ready for the third day": the sixth (of Sivan) when the Torah was given. And what did Moses do on the fifth day? He rose early in the morning and built an altar, viz. (Ibid. 24:4) "and he rose early in the morning and he built an altar at the foot of the mountain." He set up twelve monuments for the twelve tribes of Israel. These are the words of R. Yehudah.