Exodus 32:28

Overview - Exodus 32
1	The people, in the absence of Moses, cause Aaron to make a calf.
7	God informs Moses, who intercedes for Israel, and prevails.
15	Moses comes down with the tables.
19	He breaks them.
20	He destroys the calf.
22	Aaron's excuse for himself.
25	Moses causes the idolaters to be slain.
30	He prays for the people.

Exodus 32:28  (King James Version)
And the children of Levi did according to the word of Moses: and there fell of the people that day about three thousand men.