Nu’man bin Bashir (may Allah be pleased with him) reported: I heard Allah’s Messenger (may Allah bless and greet him) as having said this (and Nu’man pointed towards his ears with his fingers): What is unlawful is evident, and what is unlawful is evident, and in between them are the things doubtful which many people do not know. So he who guards against doubtful things keeps his religion and honour blameless, and he who indulges in doubtful things indulges, in fact, in unlawful things, just as a shepherd who pastures his animals round a preserve will soon pasture them in it. Beware, every king has a preserve, and the things God has declared unlawful are His preserves. Beware, in the body there is a piece of flesh; if it is sound, the whole body is sound, and if it is corrupt, the whole body is corrupt, and listen it is the heart.
Allah the Exalted, through His Messenger (may Allah bless and greet him) as well as the Holy Qur’an, has clearly defined the things which are lawful and those which are unlawful. In between these there lie certain things which are doubtful. The man who shuns the use of such things guards himself against pitfalls, since the use of doubtful things paves the way for falling into the net of evil.
At the outset no one dares commit glaring evils; he starts from the acts which apparently have no evil around them, but the intention behind them is no good. He then proceeds slowly and steadily on this dangerous path without realising the enormity of danger lying ahead and ultimately falls victim to evil.
The Holy Messenger (may Allah bless and greet him) has explained this process of moral deterioration with the help of a simile of a king’s preserve. The shepherd who does not keep his sheep from the preserve hazards misfortune. The doubtful things lying in between the lawful and the forbidden are, in fact, the borderlines, and true believers are cautioned not to go near them lest they are tempted to cross these borders.