إِلىٰ رَبِّكَ مُنتَهاها
Its outcome is with your Lord.
EXPOSITION
A deeper explanation for verse 44 may be that the final hour comes to be through the annihilation of all things and means. It manifests the reality that all power and sovereignty belongs to God, the all-mighty. It is attributed to God without any intermediary or constraint, including the constraint of a prefixed time.
The Quran never provides any specifics about the appointed day except that it coincides with the end and destruction of the world as we know it (39:68), it would be as if we live on the earth for an extremely short interval of time (verse 46 of this surah, 46:35, 30:55), and that it would be sudden. Indeed, the Quran clearly explains this point by explaining: They question you [O Muhammad] concerning the hour, when will it set in? Say: ‘Its knowledge is only with my Lord: none except Him shall manifest it at its time. It will weigh heavy on the heavens and the earth. It will not overtake you but suddenly.’ They ask you as if you were in the know of it. Say: ‘Its knowledge is only with Allah, but most people do not know’ (7:187).
[1] Mizan, 20/196-197.