Abi al-Sa’ib reported: Ali ibn Abi Talib, may Allah be pleased with him, said, “Do not frequently scold others, for scolding leads to resentment and hatred and too much of it is bad manners.”
Source: Rawḍat al-‘Uqalā’ 1/182
عَنْ أَبِي السَّائِبِ قَالَ قَالَ عَلِيٌّ بْنَ أَبِي طَالِبٍ رَضِيَ اللَّهُ عَنْهُ لا تُكْثِرِ الْعِتَابَ فَإِنَّ الْعِتَابَ يُورِثُ الضَّغِينَةَ وَالْبَغْضَةَ وَكَثْرَتُهُ مِنْ سُوءِ الأَدَبِ
1/182 روضة العقلاء لابن حبان