Dua for Leaving the Mosque
Seeking Allah's bounty when leaving His house
اَللّٰهُمَّ إِنِّي أَسْأَلُكَ مِن فَضْلِكَ وَرَحْمَتِكَ
Allahumma inni as'aluka min fadlika wa rahmatika.
O Allah, I ask You from Your bounty and mercy.