Musannaf Ibn Abi Shayba 13:1192

Abu Bakr narrated to us, he said: Abu al-Ahwas narrated to us, from Abu Ishaq, from al-Sha'bi, who said: A man claimed a mule that was in the possession of another man, and he established evidence that it was his. The one who had it in his possession also established evidence that he had bred it. Shurayh judged it for the one who had it in his possession.