´It was narrated from Abu Hurairah that:` The Prophet (ﷺ) said: "When the reciter says Amin, then say: "Amin" too, for the angels say Amin and if a person's Amin coincides with the Amin of the angels, Allah will forgive his previous sins"
Hadith ReferenceSunan an-Nasa'i / The Book of the Commencement of the Prayer / Hadith: 927
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح بخاري
Hadith Takhrij«صحیح البخاری/الدعوات 63 (6402) ، سنن ابن ماجہ/إقامة 14 (851) ، مسند احمد 2/238، (تحفة الأشراف: 13136) (صحیح)»