"The Messenger of Allah said:'For that which is watered by the sky, rivers and springs, one-tenth. For whatever is irrigated by animals, one-half of one-tenth."' (Using translation from Nasāʾī 2489)
أَنَّ رَسُولَ اللهِ ﷺ يَقُولُ فِيمَا سَقَتِ الْأَنْهَارُ وَالسَّيْلُ الْعُشُورُ وَفِيمَا سُقِيَ بِالسَّانِيَةِ نِصْفُ الْعُشُورِ