What does Leviticus 10:12 mean?

Moses told Aaron and his sons who were left, Eleazar and Ithamar, 'Take the grain offering that was left from the offerings to the Lord, and eat it without yeast beside the altar, because it's most holy.' Leviticus 10:12 - Modern Text Bible

(The priests are to eat the leftover grain offering as part of their role, following the rules for holy food.)