Hadith: The Prophet of Allah (may Allah's peace and blessings be upon him) used to say during times of distress: "There is no god but Allah, the Most Great, the Forbearing. There is no god but Allah, the Lord of the Mighty Throne. There is no god but Allah, the Lord of the heavens, the Lord of the earth, and the Lord of the Noble Throne

عَنِ ابْنِ عَبَّاسٍ رضي الله عنهما:
أَنَّ نَبِيَّ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ كَانَ يَقُولُ عِنْدَ الْكَرْبِ: «لَا إِلَهَ إِلَّا اللهُ الْعَظِيمُ الْحَلِيمُ، لَا إِلَهَ إِلَّا اللهُ رَبُّ الْعَرْشِ الْعَظِيمِ، لَا إِلَهَ إِلَّا اللهُ رَبُّ السَّمَاوَاتِ وَرَبُّ الْأَرْضِ وَرَبُّ الْعَرْشِ الْكَرِيمِ».
[صحيح] - [متفق عليه] - [صحيح مسلم: 2730]

Ibn ‘Abbās (may Allah be pleased with him and his father) reported:
The Prophet of Allah (may Allah's peace and blessings be upon him) used to say during times of distress: "There is no god but Allah, the Most Great, the Forbearing. There is no god but Allah, the Lord of the Mighty Throne. There is no god but Allah, the Lord of the heavens, the Lord of the earth, and the Lord of the Noble Throne."
[Authentic hadith] - [Narrated by Bukhari & Muslim] - [Sahih Muslim - 2730]

Explanation

The Prophet (may Allah's peace and blessings be upon him) used to say at times of intense distress and grief: "There is no god but Allah." No deity is truly worthy of worship but Allah, "the Most Magnificent" in status, the One of great significance in His essence, attributes, and actions. "The Forbearing" Who does not hasten the sinner's punishment; rather, He delays it, and He might pardon him despite having the ability to punish him, as He is the One Able to do all things. "There is no god but Allah, the Lord of the Mighty Throne,"  the Creator of the Mighty Throne. "There is no god but Allah the Lord of the heavens and the earth" and their Creator and the Creator, Possessor, Manager, and Disposer of everything therein the way He wills. "The Lord of the Noble Throne,"  the Creator of the Mighty Throne.