Sahih Bukhari
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Volume: 005 / Book Number: 059 / Hadith Number: 550
Narrated 'Abdullah:
The Prophet gave (the land of) Khaibar to the Jews (of Khaibar) on condition that they would work on it and cultivate it and they would have half of its yield.