It is narrated from Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) mounted a donkey of his called Ya'fur, whose halter was of palm fibre, and he (peace and blessings be upon him) said: "Mount, O Mu'adh." I said: Go ahead, O Messenger of Allah. He (peace and blessings be upon him) said: "Mount." So he (peace and blessings be upon him) seated me behind him. Then the donkey fell with us, and the Messenger of Allah (peace and blessings be upon him) got up laughing. Then he mounted a second time and said: "Mount." So I mounted, and the donkey went on with us for as long as Allah willed. The narrator said: He (peace and blessings be upon him) reached his hand back and struck my back with a whip - or a stick - that he had with him, and said: "O Mu'adh, son of Umm Mu'adh, do you know what the right of Allah over people is?" I said: Allah and His Messenger know best. He (peace and blessings be upon him) said: "The right of Allah over His servants is that they worship Him and do not associate anything with Him." Then he went on for as long as Allah willed, then reached his hand back and struck my back and said: "O Mu'adh, son of Umm Mu'adh, do you know what the right of the servants over Allah is when they do that?" I said: Allah and His Messenger know best. He (peace and blessings be upon him) said: "The right of the servants over Allah is that He admits them into Paradise when they do that."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17276