Once he directed a blind person to do a thing. That man went and started beating Hazrat Usman, who was praying, in the mosque. And after prayer he inquired, "What's going on!?" He said, "I thought you were such a such person. Nouman told me to that." And Nouman snickering in corner.
Prophet used to smile on it. And Prophet was also called by a scholar a laughing Prophet. His face used to be filled with smile. But he never laughed out like we use to. And what a beautiful thing is said in the Quran, "And He is the One who made you laugh and made you cry."
* Notes taken from a talk by Sheikh Hamza Yusuf. Watch.