It was narrated by al-Bukhari (59). Abu 'Ubayd said (60): 'Al-'Athari' is that which is watered by rain, and the common people call it 'al-'idhy'. The Qadi said: It is water that stagnates in a pool or similar, into which rainwater flows through channels dug for it; when it collects, it is used for irrigation. Its etymology comes from 'al-'athur', which is the channel in which water flows, because one who passes by it trips (ya'thuru) over it. In a narration by Muslim: 'And on what is watered by the saniyah (irrigation camel), there is a half-tithe' (61). 'Al-sawani' are the irrigation camels, which are camels used to draw water for irrigating the land. From Mu'adh, he said: The Messenger of Allah (peace and blessings of Allah be upon him) sent me to Yemen, and he commanded me to take a tithe from what is watered by rain or watered as 'ba'l', and a half-tithe from what is watered by a 'daliyah' (water-lifting device) (62). Abu 'Ubayd said (63): 'Al-ba'l' is that which drinks by its own roots without irrigation. In sum, everything that is watered with difficulty and expense, whether by a daliyah, saniyah, wheel (dulab), noria (na'urah), or otherwise, is subject to a half-tithe. What is watered without expense is subject to a tithe, due to the report we narrated, and because the presence of expense (kulfa) has an effect in exempting one from Zakah entirely, as evidenced by 'al-ma'lufah' (livestock fed on fodder) (64), so it is more fitting that it should have an effect in reducing it. Furthermore, Zakah is only due on growing wealth, and expense has an effect in reducing (65) that growth, so it has an effect in reducing what is mandatory upon it. The digging of rivers and channels has no effect in reducing the Zakah because the expense is minimal; it is part of the reclamation of the land and is not repeated every year. Likewise, there is no effect if it requires a water-carrier to water it and channel the water in (66)