Is it obligatory to repeat the Asr prayer after madhiy (prostatic fluid) is discharged following its completion, or is it valid to adopt the saying: "There is no need to repeat the prayer for one who prayed with an impurity they were unaware of or had forgotten"? And does the ruling on an "event" (hadath) differ from that of "impurity" (najāsa) in this case?

If it becomes apparent to the worshipper that there is madhy (pre-seminal fluid) after completing the prayer, then, according to the preponderant opinion, their prayer is valid if they had performed wudu' (ablution) before it. However, if the prayer was performed in a state of hadath (ritual impurity, such as not having wudu') due to forgetfulness or ignorance, then it is invalid and must be repeated, because ritual purity from hadath is among the commanded actions and is not waived by forgetfulness or ignorance. Whereas purity from khabath (filth/impurity) falls under the category of abstentions, and its purpose is to avoid impurity, and it does not require the action or intention of the servant.