“If he withholds it while denying that it is obligatory, a person who knows the ruling has disbelieved.”
His statement, “If he withholds it while denying that it is obligatory, a person who knows the ruling has disbelieved,” means that he refuses to pay zakat. The subject refers to the owner of zakatable wealth, while the pronoun refers to zakat.
His statement, “has disbelieved,” refers to disbelief of conviction, not disbelief through deeds, for he has believed contrary to what the Sacred Law indicates and has denied the Quran, the sunnah, and the consensus of the Muslims. If withholding zakat is combined with such denial, the matter is even more severe and grave, for it combines disbelief in conviction with sinful conduct in practice.
The reason for declaring him a disbeliever is not his withholding it, but rather his denial that it is an obligation. As for withholding it out of miserliness or negligence, this will come later in the author’s discussion. Accordingly, the author’s words, “if he withholds it while denying that it is obligatory,” are illustrative rather than a defining principle. Withholding it is not a condition for declaring one who denies its obligation a disbeliever; rather, the condition is that he deny its obligation. Thus, even if he pays it while denying that it is obligatory, he has disbelieved.
His statement, “while denying,” is an accusative of purpose, and it precedes the act, for an accusative of purpose may precede the act, accompany it, or come after it. This denial either precedes the act or accompanies it. Its preceding the act means that he says, “I am not liable for zakat; it is not obligatory.” Its accompanying the act means that he denies zakat at the time of withholding it. If he withholds it in this manner, “a person who knows the ruling has disbelieved”—that is, he disbelieves if he denies zakat while knowing that it is obligatory. This is because the obligation of zakat is a matter necessarily known to be part of the religion of Islam; every Muslim knows that zakat is obligatory. Thus, whoever denies this has disbelieved.
Here, the author, may Allah have mercy on him, qualified the ruling of disbelief by requiring that he be knowledgeable