‏الصلاة : Hadeeth No:814 Abu Harare reported: The Messenger of Allaah (sallAllaahu alayhi wa sallam) said: When anyone amongst you utters Amin and the angels In the heaven also utter Amin and (the Amin) of the one synchronises with (that of) the other, all his previous sins are pardoned....

‏اللباس والزينة‏ : Hadeeth No:5257 This hadith has been narrpted on the authority of Waki' with the same chain of transmitters but with a slight variation of wording....