It is narrated from Abdullah bin Umar (may Allah be pleased with them) that Umar bin Khattab (may Allah be pleased with him) used to take one-twentieth from wheat and oil that was irrigated by water being drawn out. He intended by this that goods should be brought in abundance to Madinah, and from pulses he used to take one-tenth (ushr).
Hadith Referenceمسند الإمام الشافعي / كتاب الزكاة / 741
Hadith Takhrijاسناده صحیح اخرجه البيهقى 9 / 210 ۔ وفى المعرفة السنن والآثار له (5542) ۔ وعبدالرزاق (10126) ، (10127)، (19282) وابن ابي شيبة (10584)۔