Sunan Abi Dawud Book 15, Hadith 90
‘Abd Allah bin Ja’far said “When the Prophet (ﷺ) arrived after a journey, we were taken for his reception. Any of us who met him first he lifted him in front of him. As I was the first to meet him, he lifted me in front of him. Then Hasan or Hussain was brought to him and he set him behind him. We the entered Madeenah and we (were) riding so (three on one beast).”
The Messenger of Allah (ﷺ) was present with a she-mule which he rode, so Ali said: If we made asses cover mares we would have animals of this type. The Messenger of Allah (ﷺ) said: Only those who do not know do that.
Abu Hurairah reported the Prophet(ﷺ) as saying “Do not treat the backs of your beasts as pulpits, for Allaah has made them subject to you only to convey you to a town which you cannot reach without difficulty and He has appointed the earth (a floor to work) for you, so conduct your business on it.