It is narrated from Sayyiduna Ali (may Allah be pleased with him), he says: The Messenger of Allah (peace and blessings be upon him and his family) forbade us from mating a mare with a donkey.
Hadith Takhrij«صحيح لغيره ، (انظر مسند أحمد ترقيم الرسالة: 738 ترقیم بيت الأفكار الدولية: 738»
Brief Explanation
Benefits: … A mule is produced from the mating of a mare and a donkey. In these ahadith, this mating has been regarded as disliked, although in the Noble Qur’an, along with horses and donkeys, the mule is also mentioned as a favor, from which the permissibility of the existence of the mule and its continuation as a species is understood. Therefore, the scholars have considered the prohibition or the ruling of dislike in these ahadith to be of a non-binding (tanzihi) nature, or it will be interpreted as applying to the situation where, due to this, the lineage and increase of horses is affected, because the horse is more beneficial and necessary than the mule, and there should not be a decrease in its lineage.