When the Prophet ﷺ began the prayer, he would say the takbir, then say, "Truly my prayer, my rites of worship, my living, and my dying are for Allah, Lord of all the worlds. He has no partner. With this I have been commanded, and I am among the Muslims. O Allah, guide me to the best of deeds and the best of character, for none guides to the best of them but You. And protect me from evil deeds and evil character, for none protects from their evil but You."
كان النبي ﷺ إذا استفتح الصلاة كبر، ثم قال: إن صلاتي ونسكي ومحياي ومماتي الله رب العالمين، لا شريك له وبذلك أمرت وأنا من المسلمين، اللهم اهدني لأحسن الأعمال وأحسن الأخلاق، لا يهدي لأحسنها إلا أنت، وقني سيئ الأعمال وسيئ الأخلاق، لا يقي سيئها إلا أنت.
Nasai (896) narrated it from Amr bin Uthman bin Saeed, who said, Shurayh bin Yazid Hadrami narrated to us, who said, Shuayb bin Abu Hamza informed me, who said, Muhammad bin Munkadir informed me, from Jabir bin Abdullah, who said, and he mentioned it. Its chain of transmission is sahih.