—namely, that the verb ashhadu (I bear witness) is used in the singular, without adding the nun that signifies majesty or a speaker who includes others.

Some brothers requested that I compose for him an introduction containing comprehensive principles that would assist in understanding the Quran, in grasping its exegesis and meanings, in distinguishing—within both what is transmitted and what is rational—between truth and the various forms of falsehood, and in pointing out the decisive proofs that separate one claim from another.

Commentary
(1) By these words the author indicates that his book was written for a reason: a brother had asked him to address this subject. An author’s work may originate independently, when he observes that people need clarification on a given topic and therefore writes about it; or it may be prompted by an external request that he treat a specific issue. The first situation represents being “asked” by the tongue of circumstance, while the second is being asked explicitly by the tongue of speech.

When a scholar notices that people require guidance on a matter and therefore composes a work about it, their very condition calls him to explain the issue into which they have fallen, so that they may know its ruling and worship Allah concerning it with clear insight. Likewise, he may be formally asked about a particular subject.

The author says “comprehensive principles.” The word qawāʿid (principles) is the plural of qāʿidah, meaning a foundation. Hence the expression qawāʿid al-bayt, the foundations of a house—its structural bases.