“الْ” (al)the Arabic equivalent of “the.” It makes the following noun specific.Corpus grammarDET — prefixed definite article.
“حَاقَّةُ” (ḥāqqahu)means “The Inevitable Reality” in this verse. It is a noun form. a word describing a doer or an action in progress. Its opening “mu-” is part of this word pattern, not a separate added word.Corpus grammarN — nominative active noun.