John Gill Commentary Jeremiah 27:13

"Why will ye die, thou and thy people, by the sword, by the famine, and by the pestilence, as Jehovah hath spoken concerning the nation that will not serve the king of Babylon?" — Jeremiah 27:13 (ASV)

Why will you die, you and your people, the sword, by the
famine, and by the pestilence
Through a blockade of the Chaldean army, which would invade their land, and besiege their city, upon a refusal to be subject to their yoke: as the Lord has spoken against the nation that will not serve the
king of Babylon ?
as the Lord has threatened shall be the case of any and everyone of the above nations that should refuse to be tributary to him; of which, no doubt, Zedekiah and his court had been apprized; see (Jeremiah 27:8) .