Halal and haram are clear

Arabic

إِنَّ الْحَلَالَ بَيِّنٌ، وَإِنَّ الْحَرَامَ بَيِّنٌ، وَبَيْنَهُمَا أُمُورٌ مُشْتَبِهَاتٌ لَا يَعْلَمُهُنَّ كَثِيرٌ مِنَ النَّاسِ، فَمَنِ اتَّقَى الشُّبُهَاتِ فَقَدِ اسْتَبْرَأَ لِدِينِهِ وَعِرْضِهِ …

Translation

The halal is clear and the haram is clear, and between them are doubtful matters about which many people do not know. Whoever avoids the doubtful safeguards his religion and his honour; whoever falls into them falls into the ḥarām — like a shepherd grazing near a private pasture, bound to enter it. Indeed in the body is a morsel: if it is sound, the whole body is sound; if it is corrupt, the whole body is corrupt — it is the heart.

Narrator

al-Nuʿmān ibn Bashīr

Source

Bukhārī 52 · Muslim 1599

Commentary

Two rulings in one hadith. Externally: stay clear of the grey zone, because the grey zone tends to become the black zone. Internally: the heart is the switchboard for the limbs — fix it and the limbs follow.