Musnad Ahmad 31:303

Yazid narrated to us, Abu al-Ashhab informed us, from Abu Nadrah, from Abu Sa’id, that the Messenger of Allah (may Allah bless him and grant him peace) looked at a man turning his riding animal among the sides of the people. The Prophet (may Allah bless him and grant him peace) said: "Whoever has a surplus of a riding animal, let him give it to the one who has no riding animal. And whoever has a surplus of provisions, let him give it to the one who has no provisions." [He continued to list things] until we thought that none of us had any right to any surplus.