Ibn Rajab reported: Imam Ahmad, may Allah have mercy on him, said, “Good character is to not get angry or enraged. Good character is to patiently endure what comes from people.”
Source: Jāmi’ al-‘Ulūm wal-Ḥikam 1/457 #18
عن ابن رجب قَالَ الْإِمَامُ أَحْمَدُ رحمه الله حُسْنُ الْخُلُقِ أَنْ لَا تَغْضَبَ وَلَا تَحْتَدَّ وَحُسْنُ الْخُلُقِ أَنْ تَحْتَمِلَ مَا يَكُونُ مِنَ النَّاسِ
1/457 #18 جامع العلوم والحكم