Abu Usaid al-Ansari reported the Messenger of Allah صلی اللہ علیہ وسلم as saying: when any of you enters the mosque he should invoke blessing on the prophet صلی اللہ علیہ وسلم and then he should say: O Allah, open to me the gates of thy mercy. And when he goes out, he should say: O Allah, I ask thee out of Thine abundance.