What does Leviticus 10:17 mean?

'Why didn't you eat the sin offering in the holy place? It's most holy, and it was given to you to take away the people's guilt and make things right for them before the Lord.' Leviticus 10:17 - Modern Text Bible

(Moses is upset because the priests didn't eat the offering as they were supposed to, which was part of their role in helping the people be forgiven.)