Exodus 24:5
And he sent young men of the children of Israel, which offered burnt offerings, and sacrificed peace offerings of oxen to the LORD.
Torrey's Topical Textbook—AKJV

Exodus 19:22
And let the priests also, which come near to the LORD, sanctify themselves, lest the LORD break forth on them.
Torrey's Topical Textbook—AKJV