Jamieson, Fausset and Brown on Jeremiah 14:18

18. go about--that is, shall have to migrate into a land of exile. Horsley translates, "go trafficking about the land (see Jr 5:31, Margin; 2Co 4:2; 2Pe 2:3), and take no knowledge" (that is, pay no regard to the miseries before their eyes) (Is 1:3; 58:3). If the literal sense of the Hebrew verb be retained, I would with English Version understand the words as referring to the exile to Babylon; thus, "the prophet and the priest shall have to go to a strange land to practise their religious traffic (Is 56:11; Eze 34:2, 3; Mi 3:11).