Abu Nu’aym reported: Wahb ibn Munnabih, may Allah have mercy on him, said, “Verily, everything has two ends and a middle. If you hold one of the ends, the other will be skewed. If you hold the middle, the two ends will be balanced. You must seek the middle ground in all things.”
Source: Ḥilyat al-Awliyā’ 4818
Ibn al-Athir said, “Every praiseworthy characteristic has two blameworthy poles. Generosity is the middle between miserliness and extravagance. Courage is the middle between cowardice and recklessness. Humanity has been commanded to avoid every such blameworthy trait.”
Source: Lisān al-‘Arab 15/209
عن أبي النعيم عن وهب بن منبه رحمه الله قال إِنَّ لِكُلِّ شَيْءٍ طَرَفَيْنِ وَوَسَطًا فَإِذَا أَمْسَكْتَ بِأَحَدِ الطَّرَفَيْنِ مَالَ الآخَرُ وَإِذَا أَمْسَكْتَ بِالْوَسَطِ اعْتَدَلَ الطَّرَفَانِ ثُمَّ قَالَ عَلَيْكُمْ بِالأَوْسَطِ مِنَ الأَشْيَاءِ
4818 حلية الأولياء وطبقات الأصفياء من الطبقة الأولى من التابعين وهب بن منبه
قَالَ ابْنُ الْأَثِيرِ كُلُّ خَصْلَةٍ مَحْمُودَةٍ فَلَهَا طَرَفَانِ مَذْمُومَانِ فَإِنَّ السَّخَاءَ وَسَطٌ بَيْنِ الْبُخْلِ وَالتَّبْذِيرِ وَالشَّجَاعَةَ وَسَطٌ بَيْنِ الْجُبْنِ وَالتَّهَوُّرِ وَالْإِنْسَانُ مَأْمُورٌ أَنْ يَتَجَنَّبَ كُلَّ وَصْفٍ مَذْمُومٍ
15/209 لسان العرب حرف الواو وسط