Jami` at-Tirmidhi 2479

Abu Burdah bin Abi Musa narrated that his father said:"O my son! If you saw us when we were with the Prophet(s.a.w) and the sky poured upon us, you would think that our smell was the smell of sheep." The meaning of this Hadith is that their garments were of wool, so when the rain fell upon them, the smell coming from their clothes was that of sheep