Is it true that Allah does not forgive a backbiter on Laylat al-Qadr?

Backbiting is forbidden by the consensus of Muslims and is considered a grave sin. The expiation of sins mentioned in the hadiths pertains to minor sins, not grave ones, for grave sins are only expiated by repentance. Indeed, Al-Hafiz Ibn Rajab clarified that the correct view is that of the majority, which holds that grave sins are not expiated without repentance. Repentance consists of regret and a firm resolve not to return to the sin. Therefore, a person who has backbitten must repent for their backbiting; otherwise, it may not be forgiven.