Dua upon entering the mosque
أَعوذُ باللهِ العَظيـم وَبِوَجْهِـهِ الكَرِيـم وَسُلْطـانِه...
أَعوذُ باللهِ العَظيـم وَبِوَجْهِـهِ الكَرِيـم وَسُلْطـانِه القَديـم مِنَ الشّيْـطانِ الرَّجـيم، بِسْـمِ الله، وَالصَّلاةُ وَالسَّلامُ عَلى رَسولِ الله، اللّهُـمَّ افْتَـحْ لي أَبْوابَ رَحْمَتـِك
aAAoothu billahil-AAatheem wabiwajhihil-kareem wasultanihil-qadeem minash-shaytanir-rajeem, bismil-lah, wassalatu wassalamu AAala rasoolil-lah, allahumma iftah lee abwaba rahmatik
Translation
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.
When to recite
Recited upon entering the mosque.
Source / Reference
Abu Dawud 1/126, Ibn Majah 1/254