Sahih Bukhari Volume 007, Book 065, Hadith Number 293.
Narrated By Anas bin Malik : Abu Talha said to Um Sulaim, "I have heard the voice of Allah's Apostle which was feeble, and I think that he is hungry. Have you got something (to eat)?" She took out some loaves of barley bread, then took her face-covering sheet and wrapped the bread in part of it, and pushed it under my garment and turned the rest of it around my body and sent me to Allah's Apostle. I went with that, and found Allah's Apostle in the mosque with some people. I stood up near them, and Allah's Apostle asked me, "Have you been sent by Abu Talha?" I said, "Yes." He asked, "With some food (for us)?" I said, "Yes." Then Allah's Apostle said to all those who were with him, "Get up!" He set out (and all the people accompanied him) and I proceeded ahead of them till I came to Abu Talha. Abu Talha then said, "O Um Sulaim! Allah's Apostle has arrived along with the people, and we do not have food enough to feed them all." She said, "Allah and His Apostle know better." So Abu Talha went out till he met Allah's Apostle. Then Abu Talha and Allah's Apostle came and entered the house. Allah's Apostle said, "Um Sulaim ! Bring whatever you have." She brought that very bread. The Prophet ordered that it be crushed into small pieces, and Um Sulaim pressed a skin of butter on it. Then Allah's Apostle said whatever Allah wished him to say (to bless the food) and then added, "Admit ten (men)." So they were admitted, ate their fill and went out. The Prophet then said, "Admit ten (more)." They were admitted, ate their full, and went out. He then again said, "Admit ten more!" They were admitted, ate their fill, and went out. He admitted ten more, and so all those people ate their fill, and they were eighty men.