Sahih Muslim
The Book of Pilgrimage (Kitab Al-Hajj)
Book Number: 007 / Hadith Number: 2688
'A'isha (Allah be pleased with her) reported: I still seem to see the glisten- ing of the perfume where the hair parted on Allah's Messenger's (may peace be upon him) head as he was in the state of Ihram, and Khalaf (one of the narrators) did not say: As he was in the state of Ihram, but said: That was the perfume of Ihram.