Sahih Muslim | Book 35 | Hadith Number 6573

Narrated by 'Ali
'Ali reported that Allah's Messenger (may peace be upon him) said to him: Say, "O Allah, direct me to the right path and make me adhere to the straight path," and when you make a mention of right guidance, keep in mind the right path and when you consider of the straight (path), keep in mind the straightness of the arrow.