If a man performs istibrāʾ after urinating and then performs wuḍūʾ, in the event that after wuḍūʾ he sees fluid that he knows to be either urine or semen, it is obligatory that as a precaution he perform ghusl as well as wuḍūʾ. However, if he had not performed wuḍūʾ, it is sufficient for him to perform wuḍūʾ only.