It is reported from Sayyiduna Ibn Abbas (may Allah be pleased with them both): The Messenger of Allah (peace and blessings be upon him) ordered us "to perform the ablution (wudu) completely," and forbade us, and I do not say he forbade you, "that we eat charity (sadaqah), or let a donkey mate with a mare."
In this chain al-Thawri named him Ubaydullah, but he is in fact Abdullah bin Ubaydullah bin Abbas; Sufyan's narration is a mistake (wahm), as al-Bukhari and others said.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب السبق والرمي / 19788