Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
ahmad-zuhd:936ʿAbdullāh > Abū Maʿmar > Sufyān b. ʿUyaynah

[Machine] The one who knows the good from the evil is not the knowledgeable person, but rather the one who knows the good and follows it, and knows the evil and avoids it.  

الزهد لأحمد:٩٣٦حَدَّثَنَا عَبْدُ اللَّهِ حَدَّثَنَا أَبُو مَعْمَرٍ عَنْ سُفْيَانَ بْنِ عُيَيْنَةَ قَالَ

لَيْسَ الْعَالِمُ الَّذِي يَعْرِفُ الْخَيْرَ مِنَ الشَّرِّ إِنَّمَا الْعَالِمُ الَّذِي يَعْرِفُ الْخَيْرَ فَيَتَّبِعُهُ وَيَعْرِفُ الشَّرَّ فَيَجْتَنِبُهُ