Hadith

 أَبِي رَحِمَهُ اَللَّهُ قَالَ حَدَّثَنَا سَعْدُ بْنُ عَبْدِ اَللَّهِ عَنْ صَفْوَانَ بْنِ مِهْرَانَ قَالَ قَالَ أَبُو عَبْدِ اَللَّهِ ع إِنَّمَا اَلْمُؤْمِنُ اَلَّذِي إِذَا غَضِبَ لَمْ يُخْرِجْهُ غَضَبُهُ مِنْ حَقٍّ وَ اَلَّذِي إِذَا رَضِيَ لَمْ يُدْخِلْهُ رِضَاهُ فِي اَلْبَاطِلِ وَ اَلَّذِي إِذَا قَدَرَ لَمْ يَأْخُذْ أَكْثَرَ من ماله مِمَّا لَهُ .

 My father, Allah may have mercy upon him, narrated to us from Sa’d bin Abdullah… from Safwan bin Mehran that Abu Abdullah (a) said: The true believer is he whose rage does not take him out of the right and whose satisfaction does not enter him into the wrong. When he has power, he should not seize more than that which is his right.

Ṣifāt al-Shīʿa

Book 1, Chapter 36