The lawful is manifest in its ruling; its permissibility is plain and unmistakable. It includes such things as bread, fruit, honey, milk, and all similar foods, drinks, garments, forms of speech, transactions, and behaviours.

Likewise, the unlawful is manifest in its ruling and its prohibition is obvious: eating pork, drinking wine, a man’s wearing of silk or gold, fornication, back-biting, tale-bearing, rancour, envy, and so on.

These two categories are clear because decisive texts have been revealed concerning them. There remains, however, a third category whose ruling is doubtful—its permissibility or prohibition unclear—and this ambiguity stems from several causes.

• One cause is the apparent conflict of proofs, so that neither reconciliation nor preference between them is evident. For the mujtahid who seeks rulings directly from the evidence, such a matter is doubtful; if he cannot discern the preponderant view, then, for him, it is a doubtful matter, and piety dictates avoiding it.

• A second cause is the clash and divergence of scholarly opinions. This concerns the lay follower (muqallid) who does not investigate the proofs; prudence for such a person lies in steering clear of what is doubtful.

• A third cause is when the prohibition of something rests on a weak hadith, casting uncertainty over its meaning.

• A fourth category comprises all acts deemed makrūh (reprehensible), for they are a stepping-stone—literally, a ladder—to the unlawful and embolden one to commit it. When the soul restrains itself even from the disliked, it shrinks from approaching them, sees them as disobedience, and thus they become a strong barrier against what is forbidden.

• A fifth cause involves permissible matters (mubāḥ) that could serve as a means to the unlawful or, in certain circumstances, lead to it; likewise, excess in lawful things can propel one into the forbidden, whether when those things are lost or simply by overindulging in them. The early generations, may Allah have mercy on them, would forgo minor lawful matters out of fear of falling into the disliked or the forbidden.

The Prophet ﷺ then illustrated the prohibitions with the protected pasture (ḥimā) that caliphs and kings reserve for their animals. He likened the one who meddles with doubtful matters to a shepherd grazing his flock around that pasture; very soon his animals are liable to stray into it because of their closeness. In the same way, whoever involves himself in doubtful matters is on the verge of falling into the unlawful. This is a striking portrayal and an easily grasped analogy.

He ﷺ next explained that there is within the body a small, delicate morsel of flesh—the heart. This heart is the sovereign that rules the kingdom of the limbs and the deeds they perform; their righteousness and the evils to which they may lead revolve entirely around it. If the heart is sound, it commands nothing but good, and the whole body is set right; but if it is corrupt, it calls to corruption and evil, and actions become inverted and perverse. Allah alone grants success.

In sum, this is a momentous and noble hadith: a foundational principle of Islam and a major pillar of the sacred law. The beams of Prophetic light shine brightly upon it and the lamp of the Divine Message illuminates it; truly, it belongs to the Prophet’s ﷺ concise, all-embracing words.