The Messenger of Allah (ﷺ) said: "When the Imam says Amin, say Amin, for if a person's Amin coincides with the Amin of the angels, his previous sins will be forgiven.'"
Sunan an-Nasa'i Book 11, Hadith 53
← Previous Hadith "The Messenger of Allah (ﷺ) said: 'When the Imam says: Not (the way) of those who earned Your anger, nor of those who went astray, say: 'Amin' for the angels say Amin and the Imam says Amin, and if a person's Amin coincides with the Amin of the angels, his previous sins will be forgiven.'"

Sunan an-Nasa'i Book 11, Hadith 52 Next Hadith → The Messenger of Allah (ﷺ) said: "When the Imam says: Not (the way) of those who earned Your anger, nor of those who went astray, say: 'Amin,' for if a person's Amin coincides with the Amin of the angels, his previous sins will be forgiven.'"

Sunan an-Nasa'i Book 11, Hadith 54