en_tn/gen/19/33.md

lay with her father

This is probably a euphemism for sexual activity. AT:"had sexual relations with her father" (See: rc://en/ta/man/translate/figs-euphemism)

when she lay down

Possible meanings are 1) these words are literal, a complement to "when she got up," or 2) they are a euphemism for sexual relations. AT: "when she had sexual relations with him" (See: rc://en/ta/man/translate/figs-euphemism)