Here the word "hand" refers to power and authority. The two phrases mean basically the same thing and emphasize Yahweh's great power. Alternate translation: "my great power" (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-doublet]])
Here the word "name" refers to Yahweh's entire person. Alternate translation: "they will know that I am Yahweh, the true God" (See: [[rc://en/ta/man/jit/figs-metonymy]])