Abu Musa Ash'ari (may Allah be pleased with him) says that he said: O my son! If you had seen us at the time when we were with the Messenger of Allah (peace and blessings of Allah be upon him) and we received rain, you would have thought that our smell was like the smell of sheep. Imam Tirmidhi says:
1- This hadith is authentic,
2- The meaning of this hadith is that the companions' clothes were made of wool, and when rainwater fell on them, they began to smell like sheep.