Rashi: It is gleaning [the remaining grapes]. After the harvest, Olelos (deficient clusters) remain, and the poor take them. So [the enemy] will plunder and return and plunder. Radak - the remnant of Yisrael are like Olelos on the vine. Malbim - a small amount of Yisrael remained, and Nebuchadnetzar came and exiled them.

Rashi: [Hashem] tells the hater to return his hand and plunder again.

Radak: Each enemy soldier tells his plunder again, until the vine will be empty.

Radak citing Targum Yonasan: Hashem tells how Yisrael will be plundered; [the enemy] will return to cut them, like harvesters putting in baskets.

Malbim: Return your hand to the harvested grapes in the basket and appear to harvest them again. I.e. after they are all exiled, he will return to exile them again. So it was - after they went out to Egypt ¹ after the Churban, the enemy overpowered a second time and returned to kill [some] and exile [others].

Rashi citing Dunash: They are searches after searches. This is like "Salselah u'Sromemeka" (Mishlei 4:8).

Rashi citing Menachem: It is an expression of a Sal (basket).

Rashi: It is one who seeks Olelos. And so it was - after exiling Yehoyakim, [Melech Bavel] killed him and made Yehoyachin king, returned after three months and exiled him, and returned after 11 years and exiled Tzidkiyah.