For Moses had said, Consecrate yourselves today to the LORD, even every man upon the cost of his son, and his brother; that he may bestow upon you a blessing this day.
All Commentaries on Exodus 32:29 Go To Exodus 32
Gregory The Dialogist
AD 604
Therefore we must consider well when we desist from chiding the wicked, how sinful it is to maintain peace with the very wicked, if so great a prophet offered to God, as it were, in sacrifice, the fact that he had aroused the enmities of the wicked against himself in behalf of the Lord. This is the reason that the tribe of Levi, when it took up the sword and passed through the midst of the host and did not spare the sinners who were to be smitten, is said to have consecrated its hand to God. Hence Phinehas, spurning the favor of his fellow countrymen, smote those associated with the Midianites and by his own wrath appeased the wrath of God.