I was a derision to all my people,.... So Jeremiah was to the people of the Jews, and especially to his townsmen, the men of Anathoth, Jer 20:7; but if he represents the body of the people, others must be intended; for they could not be a derision to themselves.
The Targum renders it, to the spoilers of my people; that is, either the wicked among themselves, or the Chaldeans; and Aben Ezra well observes, that "ammi" is put for "ammim", the people; and so is to be understood of all the people round about them, the Edomites, Moabites, and Ammonites, that laughed at their destruction; though some interpret it of the wicked among the Jews, to whom the godly were a derision; or of those who had been formerly subject to the Jews, and so their people, though not now:[and] their song all the day; beating on their tabrets, and striking their harps, for joy; for the word used signifies not vocal, but instrumental music; of such usage of the Messiah, see Ps 69:12.