The World Federation One Stop Fiqh

Ruling 793

If a person starts performing a prayer when time is short, and during it realises that his body has become impure, and he deems it probable that it became impure after he started his prayer, then, in case washing his body would not break up the prayer, he must wash his body. If it would break up the prayer, he must complete it just as he is and it will be valid.