Ja'far bin Abi Thawr narrates that Sayyiduna Jabir bin Samurah (may Allah be pleased with him) said: A man said to the Prophet (peace and blessings be upon him): Must ablution be performed after eating the meat of sheep? He said: "If you wish, perform ablution, and if you wish, do not." He said: Then may I pray in the pens of sheep? He said: "Yes."
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 1848