The Messenger of Allah ﷺ granted the people of Khaybar the right to work the land in exchange for half of its produce of fruit or crops. He used to give each of his wives one hundred wasq every year, eighty wasq of dates and twenty wasq of barley.When Umar took charge, he divided Khaybar and gave the wives of the Prophet ﷺ the choice between having a portion of land and water allotted to them, or having the wasq guaranteed to them every year. They differed in their choices. Some of them chose the land and water, while others chose the wasq each year. Ayesha and Hafsa were among those who chose the land and water.
أعطى رسول الله ﷺ خيبر بشطر ما يخرج من ثمر أو زرع، فكان يعطي أزواجه كل سنة مائة وسق: ثمانين وسقا من تمر، وعشرين وسقا من شعير. فلما ولي عمر قسم خيبر، خير أزواج النبي ﷺ أن يقطع لهن الأرض والماء، أو يضمن لهن الأوساق كل عام، فاختلفن، فمنهن من اختار الأرض والماء، ومنهن من اختار الأوساق كل عام، فكانت عائشة وحفصة ممن اختارتا الأرض والماء.
Bukhari narrated it in "Cultivation and Sharecropping" (2328), and Muslim in "Sharecropping" (1551:2), both of them through two different routes from Ubaydullah, from Nafi, from Ibn Umar, and he mentioned it. The wording given is Muslim's, and Bukhari's wording is similar, but he did not mention Hafsa.