Sayyiduna Abu Mas'ud Uqbah bin Amr (may Allah be pleased with him) said: There was a man among the Ansar called Abu Shu'ayb, and he had a slave who was a butcher. He said to his slave: "I have seen (the signs of) hunger on the face of the Messenger of Allah (peace and blessings be upon him); perhaps I may invite him as the fifth of five." So he prepared food for the Messenger of Allah (peace and blessings be upon him) and invited him (peace and blessings be upon him) as the fifth of five, and a man followed them. The Messenger of Allah (peace and blessings be upon him) said: "A man has followed us; if you wish, permit him."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 14600