Charles Ellicott Commentary Jeremiah 38:17

"Then said Jeremiah unto Zedekiah, Thus saith Jehovah, the God of hosts, the God of Israel: If thou wilt go forth unto the king of Babylon`s princes, then thy soul shall live, and this city shall not be burned with fire; and thou shalt live, and thy house." — Jeremiah 38:17 (ASV)

If you will assuredly go forth. —Literally, If going you will go, the Hebrew idiom of emphasis. The prophet places before the king the alternative of surrender and safety, resistance and destruction, and leaves him to make his choice. The princes of the king of Babylon were those in command of the army by which Jerusalem was besieged. The king himself was at Riblah, on the Orontes, in Northern Syria (Jeremiah 39:5).