Sayyiduna Abu Umamah al-Bahili (may Allah be pleased with him) narrates from the Messenger of Allah (peace and blessings be upon him) that the Messenger of Allah (peace and blessings be upon him) said: "When a man leads people in prayer, he should not single himself out for a supplication to the exclusion of them. If he does so, he has betrayed them. And no one should cast his eye into someone's house without their permission; if he does so, he has betrayed them."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5348