Riyad as-Salihin, Book 1, Hadith 76 (In-Book) ⓘ

Ibn 'Abbas (May Allah be pleased with them) said: When (Prophet) Ibrahim (Abraham) was thrown into the fire, he said: "Allah (Alone) is sufficient for us, and, He is the Best Disposer of affairs." So did Messenger of Allah Muhammad when he was told: "A great army of the pagans had gathered against him, so fear them". But this (warning) only increased him and the Muslims in Faith and they said: "Allah (Alone) is sufficient for us, and He is the Best Disposer of affairs (for us)".[Al-Bukhari].

الثالث‏:‏ عن ابن عباس رضي الله عنهما أيضاً قال‏:‏ ‏"‏حسبنا الله ونعم الوكيل، قالها إبراهيم صلى الله عليه وسلم حين ألقي في النار، وقالها محمد صلى الله عليه وسلم حين قالوا‏:‏ إن الناس قد جمعوا لكم فاخشوهم فزادهم إيمانا وقالوا‏:‏ حسبنا الله ونعم الوكيل‏:‏ ‏(‏‏(‏رواه البخاري‏)‏‏)‏‏.‏