Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrated that the Messenger of Allah (peace and blessings be upon him) passed by Ibn Sayyad while he was playing with the children, and he (peace and blessings be upon him) struck him with his foot and said: "Do you bear witness that I am the Messenger of Allah?" Ibn Sayyad said: I bear witness that you are the messenger of the unlettered. Then Ibn Sayyad said: Do you bear witness that I am the messenger of Allah? So the Messenger of Allah (peace and blessings be upon him) said: "I believe in Allah and His messengers."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13089