Jamieson, Fausset and Brown on Jeremiah 15:11

11. Verily--literally, "Shall it not be?" that is, "Surely it shall be."

thy remnant--the final issue of thy life; thy life, which now seems to thee so sad, shall eventuate in prosperity [Calvin]. They who think that they shall be the surviving remnant, whereas thou shalt perish, shall themselves fall, whereas thou shalt remain and be favored by the conquerors [Junius], (Jr 40:4, 5; 39:11, 12). The Keri reads, "I will set thee free (or as Maurer, 'I will establish thee') for good" (Jr 14:11; Ezr 8:22; Psa 119:122).

to entreat thee well--literally, "to meet thee"; so "to be placable, nay, of their own accord to anticipate in meeting thee with kindness" [Calvin]. I prefer this translation as according with the event (Jr 39:11, 12; 40:4, 5). Gesenius, from Jr 7:16; 27:18; Job 21:15, translates (not only will I relieve thee from the enemy's vexations, but) "I will make thine enemy (that now vexeth thee) apply to thee with prayers" (Jr 38:14; 42:2-6).