What is the ruling on ablution (wudu') and prayer if the impurity (najasah) is on parts of the body other than the ablution organs or on one's clothes, and what should one do if they remember the presence of impurity during ablution?

Purity of one's clothes and body is not a condition for the validity of ablution (wudu’). Thus, it is permissible to perform ablution even if there is impurity on them. However, purity of one's clothes, body, and place is a condition for the validity of prayer (salat). If a person prays with an impurity that he is unaware of, his prayer is valid. But if he prays with an impurity that he is aware of, yet ignorant of its ruling, then the opinions of scholars on this have been previously explained.