When someone sees people conversing secretly, he should not enter where they are Al-Adab Al-Mufrad 1167
Arabic hadith text
حَدَّثَنَا مُحَمَّدُ بْنُ سَلاَمٍ، قَالَ: أَخْبَرَنَا عَبْدُ الْوَهَّابِ الثَّقَفِيُّ، قَالَ: حَدَّثَنَا خَالِدٌ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ قَالَ: مَنْ تَسَمَّعَ إِلَى حَدِيثِ قَوْمٍ وَهُمْ لَهُ كَارِهُونَ، صُبَّ فِي أُذُنِهِ الْآنُكُ. وَمَنْ تَحَلَّمَ بِحُلْمٍ كُلِّفَ أَنْ يَعْقِدَ شَعِيرَةً.
Translation
Ibn 'Abbas said, "Whoever listens to people's conversations when they do not want him to do so will have molten lead poured into his ears. Anyone who lies about a dram will be obliged to string a barley bead."