Sahih Bukhari Volume 3, Book 36, Hadith Number 470.

Narated By Abu Huraira : The Prophet said, “Allah said, ‘I will be an opponent to three types of people on the Day of Resurrection:

1. One who makes a covenant in My Name, but proves treacherous.
2. One who sells a free person and eats his price.
3. One who employs a laborer and takes full work from him but does not pay him for his labour.'”