申命記 9:11 註釋：Ibn Ezra, Rabbeinu Bahya, Chizkuni & Rav Hirsch

at the mark either the beginning or the end of the forty days [cf. comment on Numbers 13: 25]. Scripture here reveals that on the very day when Moshe was given the tablets, the Golden Calf was made.

ויהי מקץ ארבעים יום וגו'...נתן ה' אלי, “it was at the end of forty days,...that the Lord gave to me the two Tablets of stone, etc.” We learn from this verse that on the very day that Moses received the Tablets the golden calf was made. Previously Moses had mentioned only: “G’d gave to me the two Tablets (verse 10), without mentioning a date. This is why here he repeats the receipt of the Tablets adding the date. This is also what Isaiah 17,11 meant when he said: “on the day that You plant you see it grow...but the branches wither away.” The word תשגשגי used for “growing” by the prophet is related to סיגים, “refuse, garbage.” This was a reference to the sin of the golden calf. Targum Yonathan there also translates Isaiah in that sense.

ויהי מקץ ארבעים יום וארבעים לילה, “it was at the end of forty days and forty nights;” these forty nights had expired at dawn on the Friday of the seventeenth day in Sivan.