اَللَّهُ أَكْبَرُ، اَللَّهُمَّ أَهِلَّهُ عَلَيْنَا بِالْأَمْنِ وَالْإِيمَانِ، وَالسَّلَامَةِ وَالْإِسْلَامِ، رَبِّي وَرَبُّكَ اللَّهُ
Transliteration
Allahu akbar, Allahumma ahillahu 'alayna bil-amni wal-iman, was-salamati wal-islam, Rabbi wa Rabbukallah
English meaning
Allah is the Greatest. O Allah, let this crescent appear over us with safety, faith, peace, and Islam. My Lord and your Lord (O moon) is Allah.
When is it recited?
Upon sighting the Ramadan crescent.
Source
Tirmidhi, Da'awat 51
