Yahya ibn al-Mukhtar reported: Hasan al-Basri, may Allah have mercy on him, said, “Love others moderately and hate others moderately. Some people were extreme in their love of others and were destroyed by it, and some people were extreme in their hatred of others and were destroyed by it. Do not be extreme in your love and do not be extreme in your hatred. Whoever finds his brother sinning beneath a veil should not expose him. Do not spy on your brother, for you have been prohibited from spying. Do not abandon him and do not alienate him.”
Source: al-Zuhd wal-Raqā’iq 651
عَنْ يَحْيَى بْنِ الْمُخْتَارِ قَالَ الحسن البصري رحمه الله أَحِبُّوا هَوْنًا وَأَبْغِضُوا هَوْنًا فَقَدْ أَفْرَطَ أَقْوَامٌ فِي حُبِّ أَقْوَامٍ فَهَلَكُوا وَأَفْرَطَ أَقْوَامٌ فِي بُغْضِ أَقْوَامٍ فَهَلَكُوا لَا تُفْرِطْ فِي حُبِّكَ وَلَا تُفْرِطْ فِي بُغْضِكَ مَنْ وَجَدَ دُونَ أَخِيهِ سِتْرًا فَلَا يَكْشِفْهُ وَلَا تَجَسَّسْ أَخَاكَ وَقَدْ نُهِيتَ عَنْ أَنْ تَجَسَّسَهُ وَلَا تَحْفِرْ عَنْهُ وَلَا تَنْفُرْ عَنْهُ
651 الزهد والرقائق لابن المبارك