'Ali ibn Rabi'a said

"I was present when 'Ali (may Allah be well pleased with him) had an animal brought for him to ride. When he placed his foot in the stirrup, he said: “In the Name of Allah [Bismillah],” and when he settled on its back, he said: “Praise be to Allah!” Then he said: “Glory be to the One who has placed this at our disposal, for we would not have been equal to the task [Subhanalladhi sakhkhara la-na hadha wa ma kunna la-hu muqrinin], and to our Lord we are surely returning [wa inna ila Rabbina la-munqalibun]. (Al-Qur'an;43:13-14)Then he said: “Praise be to Allah,” three times, and: “Allah is Supremely Great,” three times, then: “Glory be to You! I have wronged myself, so forgive me, for no one forgives sins but You!” Then he laughed, so I said to him: “What has made you laugh, O Commander of the Believers?” He said: “I saw Allah’s Messenger (Allah bless him and give him peace) do just as I did now, after which he laughed, so I said: "What has made you laugh, O Messenger of Allah ?" He replied: ‘Your Lord surely marvels at His servant when he says: “My Lord, forgive me my sins, knowing that no one but He forgives sins'!”