Musnad Ahmad 31:279

Waki' narrated to us, Shu'bah narrated to us, from Khulayd ibn Ja'far, from Abu Nadrah, from Abu Sa'id al-Khudri, who said: Musk was mentioned in the presence of the Messenger of Allah, peace and blessings of Allah be upon him, and he said: "It is the best of perfumes."