بِسْمِ اللَّهِ وَالصَّلَاةُ وَالسَّلَامُ عَلَىٰ رَسُولِ اللَّهِ، اللَّهُمَّ إِنِّي أَسْأَلُكَ مِنْ فَضْلِكَ
Bismillah, wassalatu wassalamu 'ala Rasulillah. Allahumma inni as'aluka min fadlik
In the Name of Allah, and peace and blessings be upon the Messenger of Allah. O Allah, I ask You from Your bounty.
The full Sunnah when leaving the masjid: step out with the left foot, say Bismillah, send salawat upon the Prophet ﷺ, then ask Allah for His fadl (bounty). The distinction between the entering and leaving du'as is profound — inside the masjid you sought rahmah (spiritual mercy); now heading back into the world, you ask for fadl (worldly provision and bounty). It reflects the Muslim's dual responsibility: worship inside the masjid, honest earning outside it. Both are from Allah, but you ask for each in its proper place.
Related Du'as
بِسْمِ اللَّهِ وَلَجْنَا وَبِسْمِ اللَّهِ خَرَجْنَا وَعَلَى اللَّهِ رَبِّنَا تَوَكَّلْنَا
In the Name of Allah we enter, in the Name of Allah we leave, and upon Allah our Lord we place our trust.
Sahihبِسْمِ اللَّهِ تَوَكَّلْتُ عَلَى اللَّهِ وَلَا حَوْلَ وَلَا قُوَّةَ إِلَّا بِاللَّهِ
In the Name of Allah, I place my trust in Allah, and there is no power nor strength except with Allah.
Sahihغُفْرَانَكَ
I seek Your forgiveness.
Sahihالسَّلَامُ عَلَيْنَا وَعَلَى عِبَادِ اللَّهِ الصَّالِحِينَ
Peace be upon us and upon the righteous servants of Allah.
Hasan