Is the interpretation: "until the Almighty, Omnipotent Hand points to the overwhelming, crushing wheel of the universe" for His, the Most High's, saying: (So We opened the gates of the heaven with pouring water. And We caused the earth to burst forth with springs, so the waters met for a matter already ordained) correct?

The interpretation of the verse is mostly correct, and the interpreter's literary phrasing of it is appropriate. However, attributing the action to the hand of Allah Almighty is questionable; rather, it was by the power of Allah Almighty, and His command is between the 'Kaf' and the 'Nun' (Kun - Be!). And Allah Almighty created four things with His hand.