As the sun made to set, a deep sleep fell upon Abra[ha]m; and, lo, a horror of great darkness fell upon him. And [G‑d] said to Abram: “Know surely that your descendents shall be strangers in a land that is not theirs, and they will be enslaved to them, and they will afflict them . . . [but] afterwards they will come out with great wealth . . .”
From the Torah’s description of the “Covenant Between the Pieces,” Genesis 15:12–14