[The ruling on the prayer of someone who has a water skin in him]

Answer: The scholars of the school of thought said, as stated in the footnotes to Sharh al-Azhar, regarding such a matter: If he uses a device to collect urine, his prayer is invalid, because it is an impure container, and he is not required to tie it up or stuff it. End quote.
I said: The first is to say that the prayer of the man who carries the water skin in which urine collects is valid, and that is due to the necessity of that, and that is because it is necessary for the person responsible to reduce the occurrence of impurity as much as possible, based on the evidence of the Almighty’s saying: {So fear Allah as much as you are able}. [At-Taghabun: 16], and in the hadith: “If you are commanded to do something, then do as much of it as you can.” If the sick person were to place the water skin and let the tubes run down his thighs, this would spread impurity to the body and clothes, and this would be more severe than carrying the water skin in which urine collects.

men themar alelm walhekmah