How can God's promise to humiliate the Children of Israel be reconciled with the noble verse, "It may be that your Lord will have mercy upon you; but if you return [to sin], We will return [to punishment]; and We have made Hell a prison for the disbelievers," which refers to God's mercy upon them after their destruction?

The verse: "And if you return, We will return" [Al-Isra: 8] is a promise from Allah to re-inflict punishment upon the Children of Israel if they return to corruption. And His saying: "Perhaps your Lord will have mercy upon you" [Al-Isra: 8] is a promise of mercy for them after the second punishment.

Indeed, the Children of Israel returned to corruption by disbelieving in Muhammad (peace be upon him), so Allah returned to humiliating them, as stated by Al-Qurtubi and Al-Baydawi. Allah's promise of mercy to them will be fulfilled if they do not cause corruption. Their disbelief in Muhammad (peace be upon him) is among the greatest forms of corruption, so they will not be shown mercy with this corruption of theirs. Allah may grant them respite and gradually lead them on with a kind of empowerment, in accordance with the Prophet's (peace be upon him) saying: "Indeed, Allah gives respite to the oppressor, but when He seizes him, He does not let him go."