Sahih al-Bukhari 1677

Safwan ibn Ya'la ibn Umayya related from his father, "While the Prophet, may Allah bless him and grant him peace, was at al-Ji'rana with some of his Companions, a man came to him wearing a cloak which had traces of khaluq-perfume (or he said, 'yellowness') on it and said, 'What do you order me to do in my 'umra?' Revelation came to the Prophet, may Allah bless him and grant him peace, and he was shaded by a cloth. I had been wanting to see the Prophet, may Allah bless him and grant him peace, when the revelation was descending on him. 'Umar said, 'Come on, would you like to see the Prophet, may Allah bless him and grant him peace, when Allah is sending down the revelation on him?' I said, 'Yes.' So he lifted a corner of the cloth and I looked at him and he was snoring. (I think he said, 'Snoring like a young camel.') When the state left him, he said, 'Where is the man who asked about 'umra? Take off your cloak, wash off the trace of khaluq from yourself and then wash away the yellowness. Do the same in your 'umra as you do in your hajj.'"