Charles Ellicott Commentary Exodus 32:29

"And Moses said, Consecrate yourselves to-day to Jehovah, yea, every man against his son, and against his brother; that he may bestow upon you a blessing this day." — Exodus 32:29 (ASV)

For Moses had said, Consecrate yourselves.— Moses had explained to them that a brave behaviour under existing circumstances would be accepted as a "consecration," and would win for the tribe a semi-priestly character. His announcement was made good when the Levites were appointed to the service of the sanctuary in lieu of the firstborn (Numbers 3:6–13).