The Prophet ﷺ used to send Abdullah ibn Rawahah (to Khaybar), and he would assess the amount of dates when they began to ripen before they were eaten (by the Jews). He would then give choice to the Jews that they have them (on their possession) by that assessment or could assign to them (Muslims) by that assignment, so that the (amount of) zakat could be calculated before the fruit became eatable and distributed (among the people).  

كَانَ النَّبِيُّ ﷺ يَبْعَثُ عَبْدَ اللَّهِ بْنَ رَوَاحَةَ فَيَخْرُصُ النَّخْلَ حِينَ يَطِيبُ قَبْلَ أَنْ يُؤْكَلَ مِنْهُ ثُمَّ يُخَيِّرُ يَهُودَ يَأْخُذُونَهُ بِذَلِكَ الْخَرْصِ أَوْ يَدْفَعُونَهُ إِلَيْهِمْ بِذَلِكَ الْخَرْصِ لِكَىْ تُحْصَى الزَّكَاةُ قَبْلَ أَنْ تُؤْكَلَ الثِّمَارُ وَتُفَرَّقَ  

The Prophet ﷺ used to send Abdullah ibn Rawahah (to Khaybar), and he would assess the amount of dates when they began to ripen before they were eaten (by the Jews). He would then give choice to the Jews that they have them (on their possession) by that assessment or could assign to them (Muslims) by that assignment, so that the (amount of) zakat could be calculated before the fruit became eatable and distributed (among the people). (Using translation from Abū Dāʾūd 3413)   

شَأْنَ خَيْبَرَ كَانَ النَّبِيُّ ﷺ يَبْعَثُ ابْنَ رَوَاحَةَ إِلَى الْيَهُودِ فَيَخْرُصُ عَلَيْهِمُ النَّخْلَ حِينَ يَطِيبُ قَبْلَ أَنْ يُؤْكَلَ مِنْهُ ثُمَّ يُخَيِّرُونَ يَهُودَ أَنْ يَأْخُذُوهُ بِذَلِكَ الْخَرْصِ أَمْ يَدْفَعُونَهُ إِلَيْهِمْ بِذَلِكَ؟ وَإِنَّمَا كَانَ أَمْرُ النَّبِيِّ ﷺ بِالْخَرْصِ لِكَيْ يُحْصِيَ الزَّكَاةَ قَبْلَ أَنْ تُؤْكَلَ الثَّمَرَةُ وَيُفَرَّقَ  

[Machine] The Prophet ﷺ used to send Ibn Rawaha to the Jews to ascertain the ripeness of the dates before they were eaten. Then the Jews were given the option to take them with a type of payment or to leave them and give them to the Muslims as a form of zakat (charity). The Prophet ﷺ ordered this to be done so that the zakat could be calculated before the fruits were eaten and distributed.  

شَأْنَ خَيْبَرَ «فَكَانَ النَّبِيُّ ﷺ يَبْعَثُ ابْنَ رَوَاحَةَ إِلَى الْيَهُودِ فَيَحْزُرُ النَّخْلَ حِينَ يَطِيبُ قَبْلَ أَنْ يُؤْكَلَ مِنْهُ ثُمَّ يُخَيِّرُونَ الْيَهُودَ بِأَنْ يَأْخُذُوهَا بِذَلِكَ الْخَرْصِ أَوْ يَدْفَعُوهَا إِلَيْهِمْ بِذَلِكَ وَإِنَّمَا كَانَ أَمَرَ النَّبِيُّ ﷺ بِالْخَرْصِ لِكَيْ تُحْصَى الزَّكَاةُ قَبْلَ أَنْ يُؤْكَلَ الثِّمَارُ وَيُفَرَّقَ»