It is narrated from Sayyiduna Wa'il bin Hujr (may Allah be pleased with him) that he heard the Prophet (peace and blessings be upon him), upon saying "Not of those who have earned [Your] anger, nor of those who are astray", say "Amin", and those behind him (peace and blessings be upon him) also said "Amin".
Hadith Referenceالمعجم الكبير للطبراني / باب الواو / 18260