Sayyidah Aisha (may Allah be pleased with her) narrates about the situation of Khaybar: When the dates there would ripen, but were not yet fit for eating, the Noble Prophet (peace and blessings be upon him) would send Sayyiduna Abdullah bin Rawahah (may Allah be pleased with him) to the Jews so that he could go there and estimate the date crop. After estimating, he would give them the choice that they could either take the dates according to the estimated amount and leave the crop, or pay their share according to that estimate. The command of the Noble Prophet was for the reason that the quantity of the dates should be estimated before they were eaten and distributed.

It is narrated from Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) that Sayyiduna Ibn Rawahah (may Allah be pleased with him) estimated the dates to be forty thousand wasq. Then, when he gave the Jews the choice, they preferred the fruit for themselves, and it was decided that they would pay twenty thousand wasq of dates.

Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates that the Noble Prophet (peace and blessings be upon him) sent Sayyiduna Ibn Rawahah (may Allah be pleased with him) towards Khaybar so that he could estimate the date harvest there. After estimating the harvest, he gave them the choice to either accept it or reject it if they wished. Upon hearing this decision, they said: This is the just decision, and by virtue of this, the heavens and the earth are established.

Sayyiduna Sahl bin Abi Hathmah (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: When you estimate the crop, then after it is harvested (collect this amount of zakat, but) leave one third. If you do not leave that much, then leave one fourth.