Sahih Muslim 3963

Ibn Umar (Allah be pleased with them) reported:Allah's Messenger (ﷺ) handed over the land of Khaibar (on the condition) of the share of produce of fruits and harvest, and he also gave to his wives every year one hundred wasqs: eighty wasqs of dates and twenty wasqs of barley. When 'Umar became the caliph he distributed the (lands and trees) of Khaibar, and gave option to the wives of Allah's Apostle (ﷺ) to earmark for themselves the land and water or stick to the wasqs (that they got) every year. They differed in this matter. Some of them opted for land and water, and some of them opted for wasqs every year. 'A'isha and Hafsa were among those who opted for land and water