The basic principle is that ritual purity remains in effect unless evidence establishes that it has been invalidated.
His prayer as a follower behind an imam free of this condition is valid, and his prayer as an imam leading someone afflicted with this condition is valid. These are two cases.
The third case is his leading as imam someone free of this condition. The apparent meaning of the author’s words is that this is invalid. Thus, if a person with urinary incontinence leads in prayer someone free of this condition, the follower’s prayer is invalid, as is the prayer of the imam himself, because he intended to lead someone whose following him in prayer is invalid—unless he was unaware of his own condition.
The reason given for the invalidity of his imamate is that the state of one afflicted with urinary incontinence is inferior to that of one free from it, and the follower cannot be in a higher state than the imam.
The correct view in this matter is that the imamate of one afflicted with urinary incontinence is valid, whether he leads someone in the same condition or someone sound and free of it.
The evidence for this is the generality of the Prophet’s statement, peace and blessings be upon him: “The one most versed in the Book of Allah should lead the people in prayer.” (1) This man’s prayer is valid because he has done what is required of him; and if his prayer is valid, it necessarily follows that his leading the prayer is valid.
Their statement that the follower cannot be in a higher state than the imam is refuted by the validity of the prayer of one who has performed ablution behind one who has performed dry ablution. They affirm this, even though the one who has performed ablution is in a higher state. Yet they say that the dry ablution of the one who performed it is valid. We likewise say: the ritual purity of one afflicted with urinary incontinence is also valid.
THE PRAYER IS NOT VALID BEHIND ONE WHO IS IN A STATE OF RITUAL IMPURITY OR ONE WHO HAS IMPURITY ON HIMSELF WHILE KNOWING THAT.
His statement: “The prayer is not valid behind one who is in a state of ritual impurity or one who has impurity on himself while knowing that …”