Musnad Ahmad 56:0

Safwan ibn Umayyah narrated that Safwan ibn Ya'la ibn Umayyah narrated from his father, who said: I heard the Prophet (peace be upon him) reciting in the prayer while he was in Ji'ranah. A man came to him and said, "O Messenger of Allah, what do you say about a man who has entered into Ihram for Umrah while he is wearing a shirt, having applied saffron, and having perfumed himself?" The Prophet (peace be upon him) remained silent for a while, and then the revelation came to him. Umar ibn al-Khattab signaled to me, so I came to him, and the Prophet (peace be upon him) was covered with a garment. I put my head under the garment, and behold, the Prophet (peace be upon him) was having a state like that of being asleep, breathing heavily. When he recovered, he said, "Where is the one who asked about the Umrah?" The man was brought to him, and he said, "As for the saffron, wash it off three times. As for the shirt, take it off. And do with your Umrah what you do with your Hajj."