Musnad Ahmad Hadith 20040

It is narrated from Muawiyah (may Allah be pleased with him) that once I submitted in the presence of the Messenger of Allah, "O Messenger of Allah! How much of our private parts should we cover and how much can we leave uncovered?" The Prophet (ﷺ) said, "Protect your private parts from everyone except your wife and your slave woman." I asked, "O Messenger of Allah! Some people have relatives who live with them?" The Prophet (ﷺ) said, "As much as possible, do not let them see your private parts, do not show them." I asked, "Sometimes one of us is alone?" The Prophet (ﷺ) said, "Allah is more deserving that one should feel shy before Him."