The number forty runs through the Torah like a drumbeat. Forty days of flood in Noah's time. Forty years in the wilderness. And here, in Exodus 34:28 as preserved by Targum Pseudo-Jonathan: forty days and forty nights that Moses stood before the Lord, during which he ate no bread nor did he drink water.
The Targum does not soften the detail. Moses did not fast in the ordinary human sense — a fast broken each evening, like Yom Kippur. He did not eat at all. He did not drink at all. For forty full days. This is physiologically impossible; the rabbis treated it as proof that Moses, during those weeks, had crossed out of ordinary bodily existence into the register of the angels, who themselves neither eat nor drink (see Genesis 18:8, where the angels at Abraham's tent only appear to eat).
And what did Moses do in that angelic state? The Targum says he wrote upon the other tables the words of the covenant, the Ten Words which had been written upon the former tables. He was rebuilding what had been shattered — the tablets he himself had broken when he descended to find the golden calf (Exodus 32:19). The replacement was not a lesser edition. The Ten Words were the same Ten Words. The covenant was whole.
This is a crucial theological claim. Israel's sin had not damaged the Torah itself — it had only damaged Israel's first access to it. The words remained perfect. Moses was simply the scribe, on the mountain, nourished by proximity to the Shekhinah, putting them down again.
The takeaway: in Judaism, what is broken can be written a second time. The covenant is not fragile to human failure. It is patient enough to be given twice.