Jamieson, Fausset and Brown on Jeremiah 24:2

2. figs ... first ripe--the "boccora," or early fig (see on Is 28:4). Baskets of figs used to be offered as first-fruits in the temple. The good figs represent Jeconiah and the exiles in Babylon; the bad, Zedekiah and the obstinate Jews in Judea. They are called good and bad respectively, not in an absolute, but a comparative sense, and in reference to the punishment of the latter. This prophecy was designed to encourage the despairing exiles, and to reprove the people at home, who prided themselves as superior to those in Babylon and abused the forbearance of God (compare Jr 52:31-34).