Sahih Bukhari Volume 008, Book 078, Hadith Number 686.

Narated By Zahdam bin Mudarrab : 'Imran bin Hussain said, "The Prophet said, 'The best of you (people) are my generation, and the second best will be those who will follow them, and then those who will follow the second generation." Imran added, "I do not remember whether he mentioned two or three (generations) after his generation. He added, 'Then will come some people who will make vows but will not fulfill them; and they will be dishonest and will not be trustworthy, and they will give their witness without being asked to give their witness, and fatness will appear among them.'"