What is the ruling on praying on grass irrigated with sewage water, whether it is dry or wet?

The land irrigated with sewage water is impure (najis), and the plants on it are impure if the impurity affects them externally, or if there is no barrier between the worshipper and the impure land.

However, if the impurity does not affect the external part of the plant, and there is a barrier between the worshipper and the impure land, then prayer on it is valid because it is pure. It is stated in Al-Majmou' by Al-Nawawi: "Similarly, if a tree is irrigated with impure water, all its branches and leaves are pure because all of them are offshoots of the tree and part of its growth." And in Al-Taj wal-Iklil by Al-Mawwaq: "Impure wheat, when sown and grown, is pure. Likewise, if impure water is used to irrigate a tree or vegetables, the fruit and vegetables are pure."