Sharqi ibn al-Quttami reported: Sayfi ibn Rabah, may Allah have mercy on him, said to his son, “O my son, know that quickest crime to be punished is oppression and that the worst supporter is transgression. The foundation of good character is to restrict speech, and the most evil of manners is excessively fault others.”
Source: Dhamm al-Baghy 24
عَنْ شَرْقِيِّ بْنِ الْقُطَامِيِّ قَالَ قَالَ صَيْفِيُّ بْنُ رَبَاحٍ التَّمِيمِيُّ رحمه الله لِبَنِيهِ يَا بَنِيَّ اعْلَمُوا أَنَّ أَسْرَعَ الْجُرْمِ عُقُوبَةً الْبَغْيُ وَشَرَّ النُّصْرَةِ التَّعَدِّي وَأَلأَمَ الأَخْلاقِ الضِّيقُ وَأَسْوَأَ الأَدَبِ كَثْرَةُ الْعِتَابِ
24 ذم البغي لابن أبي الدنيا موعظة بليغة