Jamieson, Fausset and Brown on Jeremiah 24:7

7. (Jr 30:22; 31:33; 32:38). Their conversion from idolatry to the one true God, through the chastening effect of the Babylonish captivity, is here expressed in language which, in its fulness, applies to the more complete conversion hereafter of the Jews, "with their whole heart" (Jr 29:13), through the painful discipline of their present dispersion. The source of their conversion is here stated to be God's prevenient grace.

for they shall return--Repentance, though not the cause of pardon, is its invariable accompaniment: it is the effect of God's giving a heart to know Him.