The mosque is the house of Allah. We enter it with the right foot and leave it with the left, and we answer the caller to prayer.
نص قرآني / حديث شريفEntering the mosque اللهم افتح لي أبواب رحمتك Allahumma iftah li abwaba rahmatik "O Allah, open for me the doors of Your mercy" (Muslim 713)
نص قرآني / حديث شريفLeaving the mosque اللهم إني أسألك من فضلك Allahumma inni as'aluka min fadlik "O Allah, I ask You of Your bounty" (Muslim 713)
نص قرآني / حديث شريفAfter the adhan اللهم رب هذه الدعوة التامة والصلاة القائمة آت محمدا الوسيلة والفضيلة وابعثه مقاما محمودا الذي وعدته Allahumma rabba hadhihid-da'watit-tammah, was-salatil-qa'imah, ati Muhammadan al-wasilata wal-fadilah, wab'athhu maqaman mahmudan alladhi wa'adtah "O Allah, Lord of this perfect call and established prayer, grant Muhammad the intercession and favour, and raise him to the praised station You promised him" (Bukhari 614)
When you hear the adhan, repeat after the caller, then say this dua.