God's made his covenant with Noah after the flood in response to Noah's sacrifice. That sacrifice shows us the necessity of the shedding of blood for the covenant of God to be fulfilled.
The promise of God to Adam after the fall, implicit in his words to the serpent in Genesis 3:15, is the mother of all the promises of God in Old and New Testaments and the acorn from which grows the mighty oak tree of God's covenant with his people maintained and enriched throughout all of…
Though the Scriptures do not tell us directly that God's relationship with Adam was covenantal, there was a promise implicit in his threat of death for eating from the tree of the knowledge of good and evil. It is best not to call this a covenant of works.
A review of Old Testament history that demonstrates that God made his covenants with his people at times of crisis, when the seed of the serpent was strong and threatening the continued existence and prosperity of his people.
God's covenants are unilateral. He always initiates them and says, I will make my covenant with you. Therefore, they are not treaties or agreements, but promises which God makes voluntarily, and by which he graciously brings men into friendship with himself.