The Bible maintains a strong theme of God’s unilateral promise to Israel. This promise was so strong that Israelites believed they were saved by virtue of being Jewish. Two of the strongest prooftexts for God’s changeability are really in context of this unilateral covenant:
Mal 3:6 “For I the LORD do not change; therefore you, O children of Jacob, are not consumed.
Heb 6:17 So when God desired to show more convincingly to the heirs of the promise the unchangeable character of his purpose, he guaranteed it with an oath,
Heb 6:18 so that by two unchangeable things, in which it is impossible for God to lie, we who have fled for refuge might have strong encouragement to hold fast to the hope set before us.
This unilateral covenant is the bedrock of Jewish theology. The striking thing is that it is unilateral.
Christine Hayes writes:
…Ancient Near Eastern parallels to the biblical covenant have been pointed out by historians. In suzerainty covenants, a superior party dictates the terms of a political treaty, and an inferior party obeys them. The arrangement serves primarily the interests of the suzerain, or superior party. In parity covenants, two equal parties agree to observe the provisions of a treaty.
There are four major covenants in the Hebrew Bible initiated by Yahweh, as expressions of divine favor and graciousness. Two of these appear in Genesis: the Noahide covenant and the Abrahamic (or patriarchal) covenant. The Noahide covenant in Gen 9: 1– 17 is universal in scope, encompassing all life on earth. The covenant stresses the sanctity of life, and Yahweh promises never to destroy all life again. By contrast, the Abrahamic covenant is a covenant with a single individual and so resembles an ancient Near Eastern suzerainty covenant. Yahweh appears as a suzerain making a land grant to a favored subject. An ancient ritual ratifies the oath— the parties to the oath pass between the split carcass of a sacrificial animal, symbolically signaling their agreement to suffer a like fate should they violate the covenant. In Gen 15, Abraham cuts several sacrificial animals in two. Yahweh, and only Yahweh, passes between the two halves. Thus, the striking thing about the Abrahamic covenant is its unilateral character. Only Yahweh is obligated by the covenant, obligated to fulfill the promise he has made. Abraham does not appear to have any obligation in return. Thus, it is the subject— Abraham— and not the suzerain— Yahweh— who is benefited by this covenant, a reversal of the reader’s expectations.
Hayes, Christine (2012-10-30). Introduction to the Bible (The Open Yale Courses Series) (Kindle Locations 1474-1486). Yale University Press. Kindle Edition.