Sahih al-Bukhari 6127

Hammad ibn Zayd related that al-Azraq ibn Qays said. "We were on the bank of a river which had dried up in Ahwaz. Abu Barza al-Aslami came riding on a horse. He prayed, leaving his horse. The horse got loose and he left the prayer and went after the horse and caught it. He brought it and then went and finished his prayer. There was a man among us who had a different opinion [to the people of the Sunna, i.e. he was a Kharijite]. He began to say, 'Look at this old man! He left his prayer because of a horse!' Abu Barza came and said, 'Since I parted from the Messenger of Allah, may Allah bless him and grant him peace, no one has rebuked me!' He continued, 'My house is far away. If I had prayed and left my horse, I would not have reached my family until night.' He mentioned that he had accompanied the Prophet, may Allah bless him and grant him peace, and had see him making things easy."