Nahj al-Balāgha
Hadith 1908وَمَنْ نَظَرَ فِي عُيُوبِ النَّاسِ فَأَنْكَرَهَا ثُمَّ رَضِيَهَا لِنَفْسِهِ فذَاك الْأَحْمَقُ بِعَيْنِهِ.
He who observes the shortcomings of others and disapproves of them and then accepts them for himself is definitely a fool.