Here the phrase "be cut off" means to be disowned and sent away. See how you translated this in [Numbers 9:13](../09/13.md). Alternate translation: "That person must be sent away" or "you must send that person away" (See: [[rc://en/ta/man/jit/figs-metaphor]] and [[rc://en/ta/man/jit/figs-activepassive]])
This can be stated in active form. Alternate translation: "no one sprinkled the water for impurity on him" (See: [[rc://en/ta/man/jit/figs-activepassive]])