Categories of Ḥadīth
The author – may Allah have mercy on him – said:
“This is a tally of the divisions of ḥadīth,
each of which he presents and defines.”

His word “dhī” is a demonstrative pronoun.

What it points to is whatever had already been arranged in the author’s mind; if the pointing preceded the writing, the referent is mental, whereas if it followed the writing, the referent is the external, present work.

What, then, is meant here by “ḥadīth”: the science of comprehension (ʿilm al-dirāyah) or the science of transmission (ʿilm al-riwāyah)?
We say that by his phrase “divisions of ḥadīth” he intends the science of comprehension.

His statement “he counted them” means that the number involved is not large.

His words “and each one he brought and defined” indicate that the author has introduced every one of these divisions.

In the expression “brought and defined,” the wāw is the wāw of accompaniment (wāw al-maʿiyyah), and “defined” (ḥaddahu) functions as a mafʿūl maʿah (accusative of accompaniment). The rule is: when something is conjoined to a hidden pronoun, it is more eloquent for the wāw to denote accompaniment and for what follows it to be in the accusative.

Accordingly, the sentence “Muḥammad came and ʿAliyyan” is more eloquent than “Muḥammad came and ʿAlī,” because the wāw of accompaniment conveys togetherness, the pronoun being the one accompanied.

The meaning of “defined” is “explained,” for a ḥadd (definition) is an explanation of a thing. A proper definition must be both inclusive and exclusive: nothing that belongs to the entity defined should be left out, and nothing alien to it should be allowed in.

Thus, defining a human being, as they say, as “a rational animal” is both inclusive and exclusive.