Authentic Supplication Number 139.

`Abdullah bin `Abbas  said: Hasbuna 'allahu wa ni`mal wakeelu (159). Ibraheem said it when he was thrown into the fire, and Muhammad said it when the people said to him "The people have united against you."(160).

Footnotes.
(159) For us Allah is sufficient, and He is the best to be entrusted [over us as guardian, provider, etc.]. This was from Surah 'Aale `Imran (#3) V.173.

(160) The original Arabic of this statement can also be found in Surat 'Aale `Imran (#3) V. 173.

Reporters.
Al-Albani sait that Al-Bukhari, and others reported it. He included this hadeeth in The Authentic of Good Sayings as #105.