Fiqh-us-Sunnah Volume 3, Zakaat and Fasting, Fiqh 3.024.

An-Nawawi says: “As for olives, our [Shaf’iyyah] view is that there is no zakah on them.” This is also the opinion of Hasan ibn Salih, Ibn Abu Layla, and Abu ‘Ubaid.

Scholars such as as-Zuhri, al-Auza’i, al-Layth, Malik, athThauri, Abu Hanifah, and Abu Thaur maintain that there is zakah on olives. Az-Zuhri, al-Layth, and al-Auza’i hold: “Determine its quantity by conjecture (yukharras), and then take its zakah in the form of olive oil,” while Malik says: “There is no need to compute its quantity by conjecture (yukharras). Take a tithe subsequent to the olives being pressed and attain the weight of five awsuq.”