From Abu Abdullah al-Nu’man ibn Bashir (may Allah be pleased with him), he said: I heard the Messenger of Allah ﷺ say: “The halal is clear, and the haram is clear, and between them are matters doubtful to which many people do not know the ruling. Whoever avoids the doubtful matters has safeguarded his religion and his honor. But whoever falls into doubtful matters falls into the haram, like a shepherd grazing his flock near a sanctuary—soon he will graze within it. Know that every king has a sanctuary, and know that Allah’s sanctuary is His prohibited matters. Know that within the body is a small piece of flesh; if it is sound, the whole body is sound, and if it is corrupt, the whole body is corrupt. Know that this piece is the heart.” Reported by al-Bukhari and Muslim.