It is narrated from Hazrat Dihyah Kalbi (may Allah be pleased with him) that once I submitted in the presence of the Messenger of Allah, "O Messenger of Allah! Should I not do this: let me mount a donkey on a horse (let them mate), so that a mule is produced and you may ride on it?" The Noble Prophet (peace and blessings be upon him) said, "This is done by those people who do not know anything."
Hadith Referenceمسند احمد / تتمہ مُسْنَدِ الْكُوفِيِّينَ / 18793
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد ضعيف لانقطاعه الشعبي لم يسمع من دحية الكلبي