Musnad Ahmad 5:103

Khalaf narrated to us, Khalid narrated to us, from ‘Asim ibn Kulayb, from Abu Burdah ibn Abi Musa, that ‘Ali said: The Prophet, may Allah bless him and grant him peace, said: "Ask Allah, the Exalted, for guidance and rectitude. And remember by guidance your guidance to the path, and remember by rectitude your aiming of the arrow."