Linguistically, what does the letter "hāʾ" refer to in the word "iqtadih" in Allah's saying: "Those are the ones whom Allah has guided. So follow their guidance [iqtadih]"?

This letter, the 'ha', is called the 'ha' of silence (sakt), the 'ha' of وقف (waqf, pause), and the 'ha' of annexation (ilḥāq); because it is added at a pause as a silent letter. For this reason, all reciters (qurrāʾ) have unanimously agreed to pause on it, following the orthography of the Mushaf, as in (يتسنه) and (كتابيه).