Al-Kāfi - The Book of al-Zakat

Al-Kāfi - The Book of al-Zakat Chapter: Grains Subject to Zakat 4ـ وَرَوَى أَيْضاً عَنْ أَبِي عَبْدِ الله (عَلَيْهِ الْسَّلا٠) أَنَّهُ قَالَ كُلُّ ٠َا دَخَلَ الْقَفِيزَ فَهُوَ يَجْرِي ٠َجْرَى الْحِنْطَةِ وَالشَّعِيرِ وَالتَّ٠ْرِ وَالزَّبِيبِ قَالَ فَأَخْبِرْنِي جُعِلْتُ فِدَاكَ هَلْ عَلَى هَذَا الأرُزِّ وَ٠ِنَ الْحُبُوبِ الْحِ٠ِّصِ وَالْعَدَسِ زَكَاةٌ فَوَقَّعَ (عَلَيْهِ الْسَّلا٠) صَدَقُوا الزَّكَاةُ فِي كُلِّ شَيْ‏ءٍ كِيلَ.

If rice is watered by rains from the sky one out of ten is Zakat but if it is watered with buckets then one out of twenty is Zakat on whatever you measure by al-Sa‘ or that he (the Imam) said, ‘Whatever is measured by measuring devices.’” رسل - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (16/23))