en_tn/2ki/06/31.md

May God do so to me, and more also

The king is saying he hopes God will punish him and even kill him if Elisha the prophet does not die because of the things that have happened in the city of Samaria. Alternate translation: "May God punish me and kill me" (See: rc://en/ta/man/jit/figs-euphemism)

if the head of Elisha son of Shaphat remains on him today

This refers to Elisha dying, specifically be being beheaded. Alternate translation: "if Elisha son of Shaphat is not beheaded today" or "if my soldiers do not behead Elisha son of Shaphat today" (See: rc://en/ta/man/jit/figs-explicit)