بِسْمِ اللَّهِ وَالصَّلَاةُ وَالسَّلَامُ عَلَى رَسُولِ اللَّهِ، اللَّهُمَّ إِنِّي أَسْأَلُكَ مِنْ فَضْلِكَ، اللَّهُمَّ اعْصِمْنِي مِنَ الشَّيْطَانِ الرَّجِيمِ
Transliteration
Bismillahi was-salatu was-salamu 'ala rasulillahi, Allahumma inni as'aluka min fadlika, Allahumma'simni minash-shaytanir-rajim
English meaning
In the name of Allah, and prayers and peace be upon the Messenger of Allah. O Allah, I ask You from Your favour. O Allah, guard me from the accursed Satan.
When is it recited?
Recited when leaving the mosque with the left foot.
Source
Abu Dawud, Salat 18, 465; Ibn Majah, Masajid 2, 773