Here "hand" represents power. Alternate translation: "Your power will seize" or "You will powerfully seize" (See: [[rc://en/ta/man/jit/figs-metonymy]])
This means the same thing as the first part of the sentence. It emphasizes that God will give the king the power to stop his enemies. (See: [[rc://en/ta/man/jit/figs-parallelism]])