Sahih Muslim
The Book Pertaining to Piety and Softening of Hearts (Kitab Al-Zuhd wa Al-Raqaiq)
Book Number: 042 / Hadith Number: 7099
Nu'man b. Bashir said: Don't you eat and drink according to your heart's desire, whereas I saw that your Prophet (may peace be upon him) (at times) could not find even an inferior quality of the dates with which he could fill his belly? Qutaiba, however, did not make a mention of It.