John Gill Commentary Jeremiah 42:16

"then it shall come to pass, that the sword, which ye fear, shall overtake you there in the land of Egypt; and the famine, whereof ye are afraid, shall follow hard after you there in Egypt; and there ye shall die." — Jeremiah 42:16 (ASV)

Then it shall come to pass that the various judgments following should come upon them: [that] the sword, which you feared, shall overtake you there in the land of Egypt; that is, the sword; of Nebuchadnezzar king of Babylon, which they feared they should fall by in Judea; this should come after them in Egypt, and there overtake them, as it did; Egypt being destroyed by the king of Babylon, as it was foretold it should, (Jeremiah 46:25Jeremiah 46:26) ;

and the famine, whereof you were afraid, shall follow close after you there in Egypt; the famine they were afraid would come upon them in Judea, should pursue them, overtake them, seize on them, and cleave unto them, in Egypt; thus the evils they thought to escape, by moving from one place, should befall them in another; there is no fleeing from the presence, power, and hand of God:

and there you shall die; either by the sword, or by famine, or by pestilence, as in the (Jeremiah 42:17) .