Musnad Ahmad 32:389

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from Anas ibn Sirin, from Anas ibn Malik, who said: There was a large man who could not pray with the Messenger of Allah, may Allah bless him and grant him peace. He said to the Prophet, may Allah bless him and grant him peace: "I cannot pray with you, so if you would come to my house and pray, I would follow your example." The man prepared food, then invited the Prophet, may Allah bless him and grant him peace. He sprinkled water on a corner of a mat of theirs, and the Prophet, may Allah bless him and grant him peace, prayed two rak'ahs. A man from the family of Al-Jarud said to Anas: "Did the Prophet, may Allah bless him and grant him peace, use to pray the Duha (forenoon) prayer?" He said: "I did not see him pray it except on that day."