Numan bin Bashir reported,

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.'"

Ibn Majah 3984

Sahih

حدثنا عمرو بن رافع حدثنا عبد الله بن المبارك عن زكريا بن أبي زائدة عن الشعبي قال سمعت

النعمان بن بشير يقول

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

ابن ماجه 3984صحيح
Contents
Reference
Commentary
Ayat
Collection
Sunan Ibn Majah
Book
Tribulations
Chapter
Stopping at doubtful matters
Numbering
Darussalam 3984
Ibn Majah 3984