Abraham did not, as indeed he could not, understand God's purposes, for the reason that Jehovah did not reveal them to him; but he knew that God had here made a covenant with him and bound it with his oath; and that by these two certain and unchangeable things, his word and his oath, God would carry out his covenant in due time, and that covenant would result in the blessing of all the families and nations of earth.
[100]The word covenant means contract; and it is the solemn form for expressing a compact, agreement, or contract between parties, or particularly on the part of one whereby he promises to do a certain thing.

With Jehovah a covenant or a contract is sacred and inviolate, because Jehovah changes not.

(Malachi 3:6) Having promised it, he will fulfill it.

(Hebrews 6:18) It is always necessary that there be two parties to a contract.

There may be more.