While on the pulpit, he gestured with his two fingers toward his ears and said, "I heard the Messenger of Allah ﷺ say, 'What is lawful is clear and what is unlawful is clear, and between the two are doubtful matters that many people do not know. Whoever guards against the doubtful matters keeps his religion and honor unblemished, and whoever falls into the doubtful matters falls into the unlawful, just like a shepherd who grazes his flock around a private pasture, on the verge of letting them graze in it. Indeed, every king has a sanctuary, and indeed the sanctuary of Allah is what He has forbidden. Indeed, in the body there is a morsel of flesh which, if sound, the whole body is sound, and if corrupt, the whole body is corrupt. Indeed, it is the heart.'"
حدثنا عمرو بن رافع حدثنا عبد الله بن المبارك عن زكريا بن أبي زائدة عن الشعبي قال سمعت
على المنبر وأهوى بإصبعيه إلى أذنيه سمعت رسول الله ﷺ يقول الحلال بين والحرام بين وبينهما مشتبهات لا يعلمها كثير من الناس فمن اتقى الشبهات استبرأ لدينه وعرضه ومن وقع في الشبهات وقع في الحرام كالراعي حول الحمى يوشك أن يرتع فيه ألا وإن لكل ملك حمى ألا وإن حمى الله محارمه ألا وإن في الجسد مضغة إذا صلحت صلح الجسد كله وإذا فسدت فسد الجسد كله ألا وهي القلب
Bukhari narrated it in the Book of Iman, chapter on the virtue of one who protects his religion, hadith no. 52, and Muslim narrated it in the Book of Musaqah, chapter on taking what is lawful and avoiding doubtful matters, hadith no. 107/1599, both from the hadith of Zakariya through this same chain.