The Prophet ﷺ said: There is no zakat payable (on grain or dates) on less than five camel-loads. The wasq (one camel-load) measures sixty sa' in weight. (Using translation from Abū Dāʾūd 1559)
عَنْ أَبِي سَعِيدٍ يَرْفَعُهُ إِلَى النَّبِيِّ ﷺ قَالَ لَيْسَ فِيمَا دُونَخَمْسَةِ أَوْسَاقٍ زَكَاةٌ وَالْوَسْقُ سِتُّونَ مَخْتُومًا