Tafsir of Fussilat 41:2

(A revelation): [This is either] by way of hyperbole or the well-known interpretation. If it is the former, it is a predicate for an elided subject, provided that Ha-Mim is regarded as being listed in the manner of enumeration according to Al-Farra’.

His saying, the Exalted: (From the Most Compassionate, the Most Merciful).

(From): This is a continuation of it, confirming the intrinsic majesty conveyed by the tanwin (indefiniteness) with relational majesty. Alternatively, it is another predicate for the elided subject, or "a revelation" is the subject, having become specific enough through what follows it to serve as its predicate.