The Prophet ﷺ used to say at the time of difficulty, 'La ilaha il-lallah Al-ʿAlimul-Halim. La-ilaha illallah Rabul- Arsh-al-Azim, La ilaha-il-lallah Rabus-Samawati Rab-ul-Ard; wa Rab-ul-Arsh Al- Karim.' (See Hadith No. 356 and 357, Vol. 8) (Using translation from Bukhārī 7426)  

أَنَّ رَسُولَ اللهِ ﷺ كَانَ يَقُولُ عِنْدَ الْكَرْبِ «لَا إِلَهَ إِلَّا اللهُ الْعَظِيمُ الْحَلِيمُ لَا إِلَهَ إِلَّا اللهُ رَبُّ الْعَرْشِ الْعَظِيمِ لَا إِلَهَ إِلَّا اللهُ رَبُّ السَّمَوَاتِ وَرَبُّ الْأَرْضِ وَرَبُّ الْعَرْشِ الْكَرِيمِ»  

Messenger of Allah ﷺ used to say at the time of difficulty, "None has the right to be worshipped but Allah, the Majestic, the Most Forbearing. None has the right to be worshipped but Allah, the Lord of the Tremendous Throne. None has the right to be worshipped but Allah, the Lord of the Heavens and the Lord of the Honourable Throne. (See Hadith No. 357, Vol. 8) (Using translation from Bukhārī 7431)  

أَنَّ النَّبِيَّ ﷺ كَانَ يَدْعُو بِهِنَّ عِنْدَ الْكَرْبُ «لَا إِلَهَ إِلَّا اللهُ الْعَظِيمُ الْحَلِيمُ لَا إِلَهَ إِلَّا اللهُ رَبُّ الْعَرْشِ الْعَظِيمِ لَا إِلَهَ إِلَّا اللهُ رَبُّ السَّمَوَاتِ السَّبْعِ وَرَبُّ الْعَرْشِ الْكَرِيمِ»