Sunan Abi Dawud 1596
سنن أبي داود#1596SahihNarrated ‘Abdallah bin Umar :The Messenger of Allah(ﷺ) as saying A tenth is payable on what is watered by rain or rivers or brooks or from underground moisture and a twentieth on what is watered by draught camels
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Bukhari (1483)
In-book reference: 9:41