The timeline is what makes the sin unbearable. Targum Pseudo-Jonathan preserves God's charge with its full sting: "Quickly have they declined from the way which I taught them in Sinai, (that) ye shall not make yourselves image, or figure, or any similitude; for now have they made to them a molten calf, and have worshipped it, and sacrificed to it" (Exodus 32:8).
What does "quickly" mean here?
The sages calculated the interval. Israel had stood at Sinai on the sixth day of Sivan and heard the Second Commandment directly from God's mouth: Thou shalt not make unto thee any graven image (Exodus 20:4). Moses had ascended the mountain shortly after and remained there forty days and forty nights (Exodus 24:18). By the midrashic calculation (Rashi on Exodus 32:1, drawing on Shabbat 89a, c. 500 CE), the calf was built on the sixteenth of Tammuz — just forty days after the giving of the commandment not to make idols.
Forty days. From "no images" spoken in the voice of God Himself, to a golden image being proclaimed as Israel's savior. The targum's word quickly captures the spiritual whiplash. This was not a slow drift. This was not a gradual forgetting. This was a direct reversal of the most explicit commandment they had ever received, within the same generation, within the same season.
The sages were harsh about this because they saw its resonance across Jewish history. How often does Israel — or any community — hear a clear word from heaven and, within a month or two, act as if it had never been spoken? The speed with which the human heart can discard a revelation is one of the most sobering themes in the targumic tradition.
And yet the story does not end here. The rapid fall will be met by rapid intercession. Moses will pray, the people will repent, and the covenant will be renewed. But the scar of Tammuz 16 will remain in the calendar as a fast day to this day.
The Maggid takes this home: nothing about revelation guarantees that revelation will be remembered. Only practice — daily, repeated, communal — keeps the word alive past its fortieth day.