en_tn/2ki/15/38.md

Jotham lay down with his ancestors

This is a polite way of saying that he died. Alternate translation: "Jotham died as his ancestors had" or "Like his ancestors, Jotham died" (See: rc://en/ta/man/jit/figs-metaphor and rc://en/ta/man/jit/figs-euphemism)

became king in his place

The phrase "in his place" is a metaphor meaning "instead of him." Alternate translation: "became king instead of Jotham" (See: rc://en/ta/man/jit/figs-metaphor)