Genesis 19:36

Thus were both the daughters of Lot with child by their father.

Cross-reference

In Genesis 19:8, Lot already offered these same daughters to the Sodomite mob — a troubling pattern of Lot's failures as a father that culminates in this incest.

Leviticus 18:7 specifically prohibits a father-daughter sexual union — the precise transgression depicted in this passage.

Deuteronomy 2:9 Historical context

Deuteronomy 2:9 names Moab — the nation descended from this very union. Lot's eldest daughter bore Moab, Israel's future neighbor.

Deuteronomy 2:19 Historical context

Deuteronomy 2:19 names Ammon — descended from Lot's younger daughter's son Ben-ammi through this same act of incest.

In Habakkuk 2:15, giving drink to expose someone's nakedness mirrors Lot's daughters getting him drunk to exploit him.