Sahih al-Bukhari 6102
Sahih al-Bukhari · Book 78: Good Manners and Form (Al-Adab) · Whoever did not admonish people in their faces
Narrated Abu Sa`id Al-Khudri:
حَدَّثَنَا عَبْدَانُ ، أَخْبَرَنَا عَبْدُ اللَّهِ ، أَخْبَرَنَا شُعْبَةُ ، عَنْ قَتَادَةَ ، سَمِعْتُ عَبْدَ اللَّهِ ـ هُوَ ابْنُ أَبِي عُتْبَةَ مَوْلَى أَنَسٍ ـ عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ ، قَالَ كَانَ النَّبِيُّ صلى الله عليه وسلم أَشَدَّ حَيَاءً مِنَ الْعَذْرَاءِ فِي خِدْرِهَا، فَإِذَا رَأَى شَيْئًا يَكْرَهُهُ عَرَفْنَاهُ فِي وَجْهِهِ.
The Prophet (ﷺ) was more shy than a virgin in her separate room. And if he saw a thing which he disliked, we would recognize that (feeling) in his face.