'Covenant' in the Bible

"Then you will know that I have sent to you this command, that my covenant with Levi {continues}," says Yahweh of hosts.

"My covenant with him was [one of] life and peace, and I gave them to him. [This required] reverence, and he revered me and stood in awe {before} my name.

But you, you have turned from the way; you have caused many to stumble by [your] instruction; you have ruined the covenant of Levi," says Yahweh of hosts.

{Do we not all have} one father? Has not one God created us? Why [then] are we unfaithful {to one another}, profaning the covenant of our ancestors?

But you ask, "{For what reason}?" Because Yahweh stands as a witness between you and the wife of your youth, against whom you have been unfaithful, even though she [is] your marriage partner and {your wife by covenant}.

"Look! I [am] going to send my messenger, and he will prepare [the] way {before me}. And the Lord whom you [are] seeking will come suddenly to his temple, and the messenger of the covenant, [in] whom you [are] taking pleasure--look!--[he is] about to come," says Yahweh of hosts.