Malachi 2:4 (KJV)

And now, O ye priests, this commandment is for you.

If ye will not hear, and if ye will not lay it to heart, to give glory unto my name, saith the LORD of hosts, I will even send a curse upon you, and I will curse your blessings: yea, I have cursed them already, because ye do not lay it to heart.

Behold, I will corrupt your seed, and spread dung upon your faces, even the dung of your solemn feasts; and one shall take you away with it.

My covenant was with him of life and peace; and I gave them to him for the fear wherewith he feared me, and was afraid before my name.

The law of truth was in his mouth, and iniquity was not found in his lips: he walked with me in peace and equity, and did turn many away from iniquity.

For the priest's lips should keep knowledge, and they should seek the law at his mouth: for he is the messenger of the LORD of hosts.

But ye are departed out of the way; ye have caused many to stumble at the law; ye have corrupted the covenant of Levi, saith the LORD of hosts.

Therefore have I also made you contemptible and base before all the people, according as ye have not kept my ways, but have been partial in the law.