(al-Bukhārī in the section on recitation) then (when the Prophet (ṣallá Allāhu ʿalayhi wa-sallam) finished reciting al-Fātiḥah, he would say: (Āmīn) aloud and prolong his voice with it) (al-Bukhārī and Muslim). He would instruct those following him in prayer to say Āmīn after the imam's Āmīn, saying: (When the imam says: not of those who have evoked [Your] anger or of those who are astray, then say: Āmīn [for the angels say: Āmīn and the imam says: Āmīn] (in another version: when the imam says Āmīn, then say Āmīn) so whoever's Āmīn coincides with the Āmīn of the angels (in another version: when one of you says in prayer: Āmīn and the angels in the sky say: Āmīn and one coincides with the other) his previous sins will be forgiven)