I heard Messenger of Allah ﷺ saying, 'Both legal and illegal things are evident but in between them there are doubtful (suspicious) 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. (O people!) Beware! Every king has a Hima and the Hima of Allah on the earth is His illegal (forbidden) things. Beware! There is a piece of flesh in the body if it becomes good (reformed) the whole body becomes good but if it gets spoilt the whole body gets spoilt and that is the heart. (Using translation from Bukhārī 52)
سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ الْحَلَالُ بَيِّنٌ وَالْحَرَامُ بَيِّنٌ وَبَيْنَهُمَا مُشْتَبِهَاتٌ لَا يَعْلَمُهَا كَثِيرٌ مِنَ النَّاسِ فَمَنِ اتَّقَى الشُّبُهَاتِ اسْتَبْرَأَ لِعِرْضِهِ وَدِينِهِ وَمَنْ وَقَعَ فِي الشُّبُهَاتِ وَقَعَ فِي الْحَرَامِ كَالرَّاعِي يَرْعَى حَوْلَ الْحِمَى يُوشِكُ أَنْ يُوَاقِعَهُ ثُمَّ إنَّ لِكُلِّ مَلِكٍ حِمًى أَلَا وَإِنَّ حِمَى اللهِ مَحَارِمُهُ أَلَا إِنَّ فِي الْجَسَدِ مُضْغَةً إِذَا صَلُحَتْ صَلُحَ الْجَسَدُ كُلُّهُ وَإنْ فَسَدَتْ فَسَدَ الْجَسَدُ كُلُّهُ أَلَا وَهِيَ الْقَلْبُ