﴿ فَسُبْحَٰنَ ٱلَّذِى بِيَدِهِۦ مَلَكُوتُ كُلِّ شَىْءٍۢ وَإِلَيْهِ تُرْجَعُونَ ﴾

“Limitless, then, in His glory is He in whose hand rests the mighty dominion over all things; and unto Him you all will be brought back!”

So glory be to Him in Whose hand is the dominion of all things malakūt means mulk the wāw and tā’ have been added for hyperbole and to Whom you will be returned restored in the Hereafter.