Sahih Bukhari Volume 3, Book 43, Hadith Number 635.

Narated By Jabala : “We were in Medina with some of the Iraqi people, and we were struck with famine and Ibn Az-Zubair used to give us dates. Ibn ‘Umar used to pass by and say, “The Prophet forbade us to eat two dates at a time, unless one takes the permission of one’s companions.”