It was narrated that Ali bin Abi Talib, may Allah be pleased with him, said: A mule was given as a gift to the Messenger of Allah and he rode it. 'Ali said: If we mate a donkey with a horse, we will have one like this. The Messenger of Allah said: That is only done by those who do not know.
It was narrated that 'Abdullah bin 'Ubaidullah bin 'Abbas said: I was with Ibn 'Abbas and a man asked him: Did the Messenger of Allah recite during Zuhr and 'Asr? He said: No. He said: Perhaps he used to recite to himself? He said: May your face be scratched! This question is worse than the first one. The Messenger of Allah was a slave whose Lord commanded him and he conveyed (the message). By Allah, the Messenger of Allah did not specify anything for us above the people, except for three things: He commanded us to perform Wudu' properly, not to consume charity, and not to mate donkeys with horses.