Musannaf Ibn Abi Shayba 36:482

Abu Khalid al-Ahmar narrated to us, from Yahya ibn Sa'id, that Umar expelled the people of Najran—the Jews and the Christians—and he purchased the open land and their vineyards. Umar made a contract with the people that if they brought the oxen and the iron (tools) from themselves, then they would have two-thirds and Umar would have one-third. And if Umar brought the seeds from himself, then he would have half. He made a contract with them regarding the palm trees on the condition that they would have one-fifth and Umar would have four-fifths. And he made a contract with them regarding the vineyards on the condition that they would have one-third and Umar would have two-thirds.