The Book Pertaining to the Excellent Qualities of the Holy Prophet (may Peace be upon them) and His Companions (Kitab Al-Fada'il)
Muslim :: Book 30 : Hadith 5660
Jabir reported that Umm Malik used to send clarified butter in a small skin to the Apostle of Allah (may peace be upon him). Her sons would come to her and ask for seasoning when they had nothing with them (in the form of condiments) and she would go to that (skin) in which she offered (clarified butter) to Allah's Apostle (may peace be upon him), and she would find in that clarified butter and it kept providing her with seasoning for her household until she had (completely) squeezed it. She came to Allah's Apostle (may peace be upon him) and (informed him about it). Thereupon, he (the Holy Prophet) said: Did you squeeze it? She said: Yes. Thereupon he said: If you had left it in that very state, it would have kept on provid- ing you (the clarified butter) on end.