An Expiation for Backbiting

Imām Ibn Taimiyyah, may Allāh have mercy on him, said:

Al-Ḥasan Al-Baṣrī said: “The expiation for backbiting [a Muslim] is that you ask [Allāh] to forgive [the sins of] the one you backbit.”

Al-Fatāwá Al-Kubrá, vol. 1, p. 113.