Musnad Ahmad 788:273

Sulayman ibn Dawud narrated to us, he said: Abu 'Awanah narrated to us, from Qatadah, from Abu Burdah, who said: Abu Musa said to me: "O my son, if you had seen us while we were with the Messenger of Allah (may Allah bless him and grant him peace) and the rain had afflicted us, you would have found the scent of sheep coming from us."