Exodus 32:29 in the King James Version
For Moses had said, Consecrate yourselves to day to the LORD, even every man upon his son, and upon his brother; that he may bestow upon you a blessing this day.
Context
28 The sons of Levi did according to the word of Moses. About three thousand men fell of the people that day.
29 Moses said, “Consecrate yourselves today to the LORD, for every man was against his son and against his brother, that he may give you a blessing today.”
30 On the next day, Moses said to the people, “You have sinned a great sin. Now I will go up to the LORD. Perhaps I shall make atonement for your sin.”