Moses Seeks To Set The Situation Right (Exodus 32:29-33).
‘And Moses said, “Consecrate yourselves today to Yahweh, yes, every man against his son, and against his brother. That he may bestow on you a blessing this day.” '
The question is, were these words spoken to the Levites, or were they spoken to the other tribesmen as they crept back and yielded?
If it was to the Levites it calls on them, having fulfilled their duty, to consecrate themselves, if necessary even at variance with sons and brothers. No human relationship must interfere with a man's consecration to Yahweh. Then He will indeed bless them. But there is no real indication of disunity among the Levites. They had acted unitedly as a tribe defending their own.
Thus we must more probably see this as Moses' response to those who had fled the camp, once they returned and were assembled. They were to submit themselves again to Yahweh regardless of what the rest of their families did. This would actually fit better the reference to choices in respect of ignoring close family, for they may have been divided by their flight. Then Yahweh would bring them back into blessing.
It may well be that it was at this point that he carried out the act of submission mentioned earlier in Exodus 32:20.
‘And it came about on the morrow that Moses said to the people, “You have sinned a great sin. And now I will go up to Yahweh. It may be that I will make atonement for your sin.” And Moses returned to Yahweh, and said, “Oh, this people have sinned a great sin, and have made for themselves a god of gold. Yet now if you will forgive their sin --, and if not, blot me I pray you out of the book which you have written.” '
But Moses knew that the death of the three thousand men had not removed the guilt of the whole, and Moses now calls on them on the day after their consecration and warns them how serious their sin has been. They had deliberately and flagrantly disobeyed God's commandments in a major way within weeks of accepting the covenant. It was a great sin indeed. He could give them no guarantees but he promised that he would again go up to Yahweh, and this time he would pray that they might be forgiven. It is clear that he was now confident that things were under control. New leaders had no doubt been appointed, with Joshua there to give Aaron vital support. And the three thousand who had died may well have included some of his most bitter opponents.
This period of prayer also lasted forty days and forty nights (Deuteronomy 9:19), that is, over a moon period. It was a triumph of persevering prayer. Spiritual battles are not easily won.
His prayer was typical of the man. He prayed that if God would not forgive them then he must blot Moses' own name out of his book. This book was probably the book of the living. Some cities and tribes would have records which contained the names of all living members of the city or tribe (Isaiah 4:3; Psalms 69:28; Malachi 3:16). When a person died his name was blotted out. Or it may be the book that contained the names of prominent men, the book of ‘heroes', from which a name would be blotted out if the hero later brought shame on his city or tribe. He was ready to sacrifice his fame and become an outcast.
Some see it as the book of eternal life, but Moses nowhere indicates belief in such a concept, and he would surely have seen it as blasphemy to interfere with such a book, however strongly he felt. Whichever it is, the principle is the same. He was willing to lose all rather then see these people (who had recently planned to kill him) suffer.