Sahih Bukhari Volume 008, Book 078, Hadith Number 679.
Narated By Anas bin Malik : Abu Talha said to Um Sulaim, "I heard the voice of Allah's Apostle rather weak, and I knew that it was because of hunger. Have you anything (to present to the Prophet)?" She said, "Yes." Then she took out a few loaves of barley bread and took a veil of hers and wrapped the bread with a part of it and sent me to Allah's Apostle. I went and found Allah's Apostle sitting in the mosque with some people. I stood up before him. Allah's Apostle said to me, "Has Abu Talha sent you?" I said, ' Yes. Then Allah's Apostle said to those who were with him. "Get up and proceed." I went ahead of them (as their forerunner) and came to Abu Talha and informed him about it. Abu Talha said, "O Um Sulaim! Allah's Apostle has come and we have no food to feed them." Um Sulaim said, "Allah and His Apostle know best." So Abu Talha went out (to receive them) till he met Allah's Apostle.
Allah's Apostle came in company with Abu Talha and they entered the house. Allah's Apostle said, "O Um Sulaim! Bring whatever you have." So she brought that (barley) bread and Allah's Apostle ordered that bread to be broken into small pieces, and then Um Sulaim poured over it some butter from a leather butter container, and then Allah's Apostle said what Allah wanted him to say, (i.e. blessing the food). Allah's Apostle then said, "Admit ten men." Abu Talha admitted them and they ate to their fill and went out. He again said, "Admit ten men." He admitted them, and in this way all the people ate to their fill, and they were seventy or eighty men."