"Sahl bin Abi Hathmah came to us when we were in the market and said: "The Messenger of Allah said: When you have estimated, take two-thirds (of the portion you have estimated as Zakah) and leave one-third, and if you do not take (two-thirds) or leave one-third. (One of the reporters) Shu 'bah doubted - leave one quarter." (Using translation from Nasāʾī 2491)  

قَالَ رَسُولُ اللهِ ﷺ «إِذَا خَرَصْتُمْ فَخُذُوا وَدَعُوا الثُّلُثَ فَإِنْ لَمْ تَأْخُذُوا أَوْ تَدَعُوا شَكَّ شُعْبَةُ فَدَعُوا الرُّبُعَ»