Exodus 32:29

29 Then Moses said, “You have been set apart to the LORD today, for you were against your own sons and brothers, and he has blessed you this day.”

Read Exodus 32:29 Using Other Translations

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.
And Moses said, "Today you have been ordained for the service of the LORD, each one at the cost of his son and of his brother, so that he might bestow a blessing upon you this day."
Then Moses told the Levites, “Today you have ordained yourselves for the service of the LORD, for you obeyed him even though it meant killing your own sons and brothers. Today you have earned a blessing.”