Muhammad quietly led the march on Khaybar oasis on 7 May AH/ 629 CE with approximately 1500 men and 100–200 horses. Primary sources including the "Sirah Rasul Allah" (Biography of the Prophet) of Ibn Ishaq describe the conquest of Khaybar, detailing the agreement of Muhammad with the Jews to remain in Fadak and cultivate their land, retaining one-half of the produce of the oasis. This agreement was distinct from the agreement with the Jews of Khaybar, which essentially entailed the practice of sharecropping. Muhammad retained the revenues of the Fadak region for the poor as "ṣadaqa", travelers in need, and for his family.