إِنَّ إِلَىٰ رَبِّكَ ٱلرُّجْعَىٰ
The grammatical structure of the sentence is striking. After the particle inna the noun (the subject) normally comes first and the predicate after: inna'r-rujʿā ilā rabbik. The verse breaks this order and brings the predicate forward: inna ilā rabbika r-rujʿā.
In Arabic a fronted element conveys restriction (ḥaṣr). We saw the same technique in the last verse of Sūrat al-Ikhlāṣ: there lahu had been fronted, and the sense "to Him in particular there is no equal" arose.
Here the sense becomes: the return is only to your Lord. There is no other place of return, no other seat of appeal. And this is a direct answer to the preceding verse: the man was seeing himself as sufficient; the verse does not say "you are not sufficient", it says "where you are going is settled". The claim of istighnāʾ is refuted by a reminder of the destination.
Pattern: fuʿlā. This is a verbal-noun pattern rarely seen in Arabic and is generally used for verbal nouns that have become the name of a thing, that have turned into concepts: bushrā (good news), dhikrā (reminder), ḥusnā (the most beautiful), ʿuqbā (the outcome).
That is, the verse does not say "you will return"; it says "the return". A noun is used in place of a verb, and the noun turns the event into a concept. A verb recounts an event; a noun establishes a fact.
The word also comes with the definite article: al-rujʿā. That is, not "a return" but "the return" — the known, the awaited, the unavoidable one.
There is a nicety in the verse: it says "to your Lord", not "to your Lord". That is, the second person singular: your Lord. The one addressed is not the human being whose transgression is being recounted; it is the addressee from the beginning of the sūra — the Prophet.
This is an instance of a shift of address (iltifāt — the changing of the direction of address). In the middle of a picture recounted in the third person, there is a sudden turn to the second person.
1. Consolation. While the depiction of the transgressor continues, a fixed point is given to the one addressed: do not mind his state, the return is to your Lord. The same name (Lord) had also occurred in the first verse; the name that gives the command "read" in the first verse is here the name of which it is said "the return is there". Beginning and destination are in the same place.
2. Connection. The first half of the sūra had begun "in the name of your Lord"; this verse of the second half says "the return to your Lord". The two halves are stitched to each other with the same word.
One more note: the verse does not say "the return to God", it says "the return to your Lord". The place to be returned to is not a foreign seat of appeal; it is the one who brought you up. In the discussion of al-Fātiḥa we treated this root's sense of "the one who nurtures, who brings to completion". To return to the one who brought you up carries a different resonance from being brought before a court — and the sūra uses this name at the very head of the section of threat.