عَنْ سَهْلِ بْنِ أَبِي حَثْمَةَ رَضِيَ اللَّهُ عَنْهُ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ: ((إِذَا خَرَصْتُمْ فَجُذُّوا، وَدَعُوا الثُّلُثَ، فَإِنْ لَمْ تَجُذُّوا أَوْ تَدَعُوا فَدَعُوا الرُّبُعَ))
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.