اللَّهُمَّ إِنِّي أَسْأَلُكَ مِنْ فَضْلِكَ
Purpose Ask Allah for His bounty when leaving the masjid.
When to Use Read this when leaving a masjid.
Source Sahih Muslim

Transliteration

Allahumma inni as`aluka min fadlik.

Meaning

O Allah, I ask You from Your bounty.