Narrated Ibn 'Abbas: The Prophet used to say at the time of difficulty, 'La ilaha il-lallah Al-'Alimul-Halim. La-ilaha il-lallah Rabul- Arsh-alAzim, La ilaha-il-lallah Rabus-Samawati Rab-ul-Ard; wa Rab-ul-Arsh Al-Karim.' (See Hadith No. 356 and 357, Vol. 8)
— Sahih Bukhari, Volume 9, Book 93: Oneness, Uniqueness of Allah (Tawheed), Hadith #523