Genesis 15:1-21
Abram falls into a deep sleep while a smoking firepot and a flaming torch pass alone between the halved animals. The covenant is cut without his participation. One verse later, Yahweh reckons his faith as righteousness — a half-verse Paul will quote four times in Romans 4 alone. Gen 15 is the locus of the unilateral covenant, the chapter where God himself walks under the self-curse, and the OT verse from which the New Testament builds its entire grammar of grace.
Genesis 12:10-13:18
A heavy famine drives Abram down; a heavy wealth carries him back up. Between the two, Yahweh strikes Pharaoh with great plagues — the first plague-word in the canon. Then Lot lifts his eyes and chooses the plain that is about to burn, and Yahweh tells Abram to lift his eyes and see the land he will give to his seed forever. Gen 12:10–13:18 is the miniature Exodus that frames the covenant's first 'forever.'
Jeremiah 31:31–34
The four covenants — Abrahamic, Mosaic, Davidic, New — form one escalating line of promise, not two parallel tracks. The same covenant formula runs from Genesis 17 to Revelation 21, and the olive tree is one.