Musannaf Ibn Abi Shayba 13:1317

Abu Bakr narrated to us, he said: Ibn Fudayl narrated to us, from ‘Asim ibn Kulayb, from Muhammad ibn Ka‘b, who said: I sold a mule to a man, and he remained for as long as Allah willed. Then he came to me, and I recognized the mule as being mine. So we went to Shurayh, and I went with the one from whom it was [taken]. He brought seven witnesses that it was his animal, that it had not been sold and had not been gifted. The other came with six witnesses that it was his animal, that it had not been sold and had not been gifted. Shurayh said: "I bear witness that one of the two parties is lying." So he divided it between them into thirteen shares, and gave each one of them according to the portion of his witnesses.