It is narrated from Sayyiduna Thawban (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: It is not lawful for any Muslim to look inside someone’s house without permission; if he does so, it would mean that he has entered. Also, no person should lead people in prayer in such a way that he supplicates only for himself; if he does so, it would mean that he has betrayed them. And no person should pray while restraining urine or feces; he should first relieve himself.