Sayyiduna Awf bin Malik (may Allah be pleased with him) related that the Prophet (peace and blessings be upon him) judged between two men, and the one against whom judgement was given said: Allah is sufficient for me, and He is the best Disposer of affairs. The Prophet (peace and blessings be upon him) said: "Bring the man back to me." Then he said: "What did you say?" He told him (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Allah blames helplessness (and negligence); hold fast to sound planning and shrewdness, and when a matter overpowers you, then say: Allah is sufficient for me, and He is the best Disposer of affairs."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 15230