Exodus Exodus 17:1-7
At Rephidim Israel quarrels and tests YHWH for water, asking 'Is YHWH among us or not?' — and YHWH answers by standing on the rock and having Moses strike it once with the rod that struck the Nile. Paul names the event: 'the rock was Christ' — struck once for all, the source of the living water that becomes the Spirit and the river of life.
Exodus Exodus 16
At the Wilderness of Sin, YHWH rains bread from heaven as a daily test of trust, coins the word 'sabbath' before Sinai, and gives Israel a perishable gift designed to end at Canaan — a downpayment on an imperishable bread and an imperishable rest.
Exodus Exodus 15:22-27
Three days past the sea, at bitter Marah, YHWH sweetens the water by a tree, binds Israel under the first statute before Sinai, and names himself for the first time as the one healing you — a covenant title the whole canon receives.
Genesis Genesis 21:1–34
Genesis 21 opens with the verb that will become the canon's word for divine intervention and closes with the divine epithet that will become the canon's word for God's eternity. Between them the narrator stages a birth, an expulsion, a wilderness rescue, a seven-fold oath, and a tamarisk planted at a well. Sarah speaks the Edenic expulsion-verb in the imperative; Yahweh ratifies her. God opens Hagar's eyes the way Eden's were opened, but to a well of water this time. The chapter is built as the Akedah's dress rehearsal, and two of its verses become the most exact verbatim citations of Genesis in the New Testament.
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.