'Consecrate' in the Bible

Then the priest is to offer one for a sin offering and the other for a burnt offering to make atonement for him because of the guilt he incurred on account of his contact with the dead body. Then he is to consecrate his head on that day.

"But give this command to the people: "You are to consecrate yourselves, because tomorrow you're going to eat meat, since you've complained where the LORD can hear it, "Who can give us meat to eat? After all, life was better with us in Egypt." Therefore, the LORD is going to give you meat and you'll eat

But the LORD rebuked Moses and Aaron, telling Moses: "Because you both didn't believe me, because you didn't consecrate me as holy in the presence of the Israelis, you won't be the ones to bring this congregation into the land that I'm about to give them."