When one of you enters the Masjid, let him say:
اللَّهُمَّ افْتَحْ لِي أَبْوَابَ رَحْمَتِكَ
TRANSLATION:
O Allah, open to me the gates of Your mercy.
Narrated: Fatimah (ra)
Whenever the Messenger of Allah (ﷺ) entered the mosque he would say:
بِسْمِ اللَّهِ وَالسَّلاَمُ عَلَى رَسُولِ اللَّهِ
اللَّهُمَّ اغْفِرْ لِي ذُنُوبِي وَافْتَحْ لِي أَبْوَابَ رَحْمَتِكَ
TRANSLATION:
In the Name of Allah, and peace be upon the Messenger of Allah. O Allah, forgive me my sins and open to me the gates of Your mercy.
Haiwah bin Shuraih said:
"I met 'Uqbah bin Muslim, and told him: 'I have heard that you narrate from 'Abdullah bin 'Amr bin Al- 'As that the Prophet (ﷺ) would say, when he entered the Masjid:
أَعُوذُ بِاللَّهِ الْعَظِيمِ وَبِوَجْهِهِ الْكَرِيمِ وَسُلْطَانِهِ الْقَدِيمِ مِنَ الشَّيْطَانِ الرَّجِيمِ
He ('Uqbah) said: 'Is that all?' I said: 'Yes.' So he (added): 'So when he says that, Shaitan says: "He has been protected from me for the entire day."
TRANSLATION:
I seek refuge in Allah, the Great, and in His Noble Face and His Eternal Power, from Shaitan, the rejected.