Lady Aisha (may Allah be pleased with her) narrates regarding the gardens of Khaybar that the Messenger of Allah (peace be upon him) used to send Sayyiduna Ibn Rawahah (may Allah be pleased with him) to Khaybar as soon as the dates ripened, and he would estimate the quantity of the dates before they were eaten. Then he would give the Jews the option to take their share according to that estimate, or the Jews could pay (the Muslims) their share according to that estimate. And indeed, the Messenger of Allah (peace be upon him) ordered the estimation so that the amount of zakat could be determined before the dates were eaten and distributed.