and forbidding what is wrong. When His command specifies particular attributes, one must know that they are present. Just as we are not obedient when we know that obedience is absent, we are not obedient unless we do not know that it is present. Rather, ignorance of its presence is like knowledge of its absence, in that both constitute disobedience. Thus, when exchanging commodities subject to the rules of usury for others of the same kind, not knowing that the quantities are equal is like knowing that they are unequal. If we do not know that they are equal, it is as though we knew that they were unequal.
As for knowing what one must abandon and forbid, a general knowledge of it may suffice in some circumstances. A person needs to recognize what is wrong and oppose it. He may also need evidence that makes this clear, answers to the counterarguments advanced by those who practise it, and the means to resist their desires and intentions. This requires firm resolve and the ability to act accordingly, neither of which is possible without patience. As Allah, Exalted is He, says:
“By time! Surely mankind is in loss, except those who believe, do righteous deeds, and urge one another to truth and urge one another to patience.”
The first step is to mention such statements and actions in a manner that condemns them, forbids them, and explains the corruption they contain. For opposing wrong in the heart and with the tongue precedes opposing it by physical action. This is the Quran’s approach when Allah, Exalted is He, recounts the statements and actions of disbelievers, the defiantly disobedient, and sinners. He mentions them in a manner that expresses condemnation and hatred of those statements and actions and those responsible for them, explains their corruption and their opposites, and warns against them. Likewise, what He recounts concerning people of knowledge and faith—including His prophets and His righteous allies—is presented with praise and love, explaining its goodness and benefit and encouraging it. An example is His saying, Exalted is He: “And they say, ‘He has taken