Dua Enter Masjid; This is the dua for entering and leaving the masjid.
Dua Enter Masjid
أَعوذُ بِاللّهِ العَظِيـمِ، وَبِوَجْهِـهِ الكَرِيـمِ وَسُلْطـَانِه القَدِيـمِ، مِنَ الشَّيْـطَانِ الرَّجِـيمِ، [ بِسْـمِ اللّهِ وَالصَّلَاةُ ] [وَالسَّلامُ عَلَى رَسُولِ اللّهِ]، اَللَّهُـمَّ افْتَـحْ لِي أَبْوَابَ رَحْمَتـِكَ.
Transliteration
aAAoothu billahil-AAatheem wabiwajhihil-kareem wasultanihil-qadeem minash-shaytanir-rajeem, [bismil-lah, wassalatu] [wassalamu AAala rasoolil-lah] , allahumma iftah lee abwaba rahmatik.
Translation in English
I take refuge with Allah, The Supreme and with His Noble Face, and His eternal authority from the accursed devil. In the name of Allah, and prayers and peace be upon the Messenger of Allah. O Allah, open the gates of Your mercy for me.
Source; Abu Dawud: 4591
Dua When Leaving The Masjid
بِسْمِ اللّهِ وَالصَّلاَةُ وَالسَّلاَمُ عَلَى رَسُولِ اللّهِ، اَللَّهُـمَّ إِنِّي أَسْأَلُكَ مِنْ فَضْـلِكَ، اَللَّهُـمَّ اعْصِمْنِـي مِنَ الشَّيْـطَانِ الرَّجِـيمِ.
Transliteration
Bismil-lah wassalatu wassalamu AAala rasoolil-lah, allahumma innee as-aluka min fadlik, allahumma iAAsimnee minash-shaytanir-rajeem.
Translation in English
In the name of Allah, and prayers and peace be upon the Messenger of Allah. O Allah, I ask You from Your favour. O Allah, guard me from the accursed devil.
Sources; Muslim: 1:494, Ibn Majah: 1:129
