Genesis 17:15-27
Same theophany, second petuchah. Gen 17:15-27 names what Gen 17:1-14 inscribed. Sarai becomes Sarah; Abraham laughs inwardly at the announcement and the child is named for the laugh; God says aval - truly - and the covenant narrows from Abraham's seed generally to one named son not yet conceived. Ishmael receives the creation-mandate blessing every nation can receive; Isaac receives the berit olam. At Mamre the angel will quote this annunciation back: shall a word be impossible with God? Luke quotes the angel back over Mary. The child's name is the disbelief converted into gift, and the seed-bearer is the woman God blesses by name.
Genesis 16:1-16
An Egyptian slave woman flees into the desert, and the angel of Yahweh finds her at a spring. By the time she leaves the spring, she has named God — the only human in the Hebrew Bible ever to do so. Gen 16 is the chapter where humanity first tries to help the covenant along, and the chapter where the helper, broken and named El-Roi by the woman she abused, hears for the first time the Exodus formula a slave will hand to a nation.
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.'
Genesis 11:10-32
The Babel-builders said na'aseh-lanu shem — let us make for ourselves a name. Eight verses later the text answers them with a different shem entirely: eleh toledot Shem — these are the generations of Shem. The line through which the name-promise will travel is literally called Name. Ten generations descend from that line, then narrow into the toledot of Terah and stop in Ur Kasdim with a barren wife, an idol-serving father, and a brother dead in the family's birth-land. Out of those three impossibilities YHWH calls one man into a moledet he must leave for a patris he must seek.