Abu Hurairah (May Allah be pleased with him) reported:
A man came to the Prophet (sallallaahu ’alayhi wa sallam) and said; “I am hard pressed by hunger.” He (sallallaahu ’alayhi wa sallam) sent a word to one of his wives who replied: “By Him Who has sent you with the Truth, I have nothing except water.” Then he sent the same message to another (wife) and received the same reply. He sent this message to all of them (i.e., his wives) and received the same reply. Then he (sallallaahu ’alayhi wa sallam) said, “Who will entertain this (man) as guest?” One of the Ansar said: “O Messenger of Allah, I will.” So he took him home and said to his wife: “Serve the guest of Messenger of Allah (sallallaahu ’alayhi wa sallam).”
Another narration is: The Ansari asked his wife: “Have you got anything?” She answered: “Nothing, except a little food for the children.” He said: “Keep them busy with something, and when they ask for food put them to sleep. When the guest enters, extinguish the light and give him the impression that we are also eating.” So they sat down and the guest ate and they passed the night hungry. When he came to the Prophet (sallallaahu ’alayhi wa sallam) in the morning, he said to him, “Allah admired what you did with your guest last night.”[Al-Bukhari and Muslim].
Allah, the Exalted, says:
“And give them (Emigrants) preference over themselves, even though they were in need of that.”(59:9)
“And they give food, in spite of their love for it (or for the love of Him), to the poor, the orphan, and the captive.” (76:8)
Source: Riyad-us-Saliheen English Publication, DarusSalam publishers