Sayyiduna Imran (may Allah be pleased with him) said: A man said: "O Messenger of Allah, I have accepted Islam; what do you command me?" He (peace and blessings be upon him) said: Say: "Allahumma inni astahdika amri, wa a'udhu bika min sharri nafsi (O Allah, I ask You for guidance in my affair, and I seek refuge in You from the evil of my own self)."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 15314