Tribute, Spoils, and Rulership (Kitab Al-Kharaj, Wal-Fai' Wal-Imarah)
Dawud :: Book 19 : Hadith 3008
Narrated Bashir ibn Yasar:
When Allah bestowed Khaybar on the Apostle of Allah (peace_be_upon_him) as fay' (spoils of war without fighting), he divided the whole into thirty six lots. He put aside a half, i.e. eighteen lots, for the Muslims. Each lot comprised one hundred shares, and the Prophet (peace_be_upon_him) was with them. He received a share like the share of one of them.
The Apostle of Allah (peace_be_upon_him) separated eighteen lots, that is, half, for his future needs and whatever befell the Muslims. These were al-Watih, al-Kutaybah, as-Salalim and their colleagues. When all this property came in the possession of the Prophet (peace_be_upon_him) and of the Muslims, they did not have sufficient labourers to work on it. The Apostle of Allah (peace_be_upon_him) called Jews and employed them on contract.