Sahih al-Bukhari #52

إِنَّ الْحَلاَلَ بَيِّنٌ وَإِنَّ الْحَرَامَ بَيِّنٌ وَبَيْنَهُمَا مُشْتَبِهَاتٌ لاَ يَعْلَمُهُنَّ كَثِيرٌ مِنَ النَّاسِ

The Prophet (ﷺ) said, "Both legal and illegal things are evident but in between them there are doubtful things and most of the people have no knowledge about them. So whoever saves himself from these suspicious things saves his religion and his honor. And whoever indulges in these suspicious things is like a shepherd who grazes his animals near the Hima (private pasture) of someone else and at any moment he is liable to get in it."