It is narrated from Sayyiduna Abu Mas'ud (may Allah be pleased with him) that a man from the Ansar whose kunyah was Abu Shu'ayb said to his slave: "Hey! I have seen (the signs of) hunger on the face of the Messenger of Allah (peace and blessings be upon him), so prepare enough food for five men." He prepared it, and Abu Shu'ayb sent word to the Messenger of Allah (peace and blessings be upon him) and invited him. A man who had not been invited followed them, and the Messenger of Allah (peace and blessings be upon him) said: "This man has followed us; do you permit him?" He said: "Yes."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 14598