To arise or stand up is a metaphor for no longer watching and thinking and instead beginning to act. AT: "will I begin to act" (See: [[rc://en/ta/man/translate/figs-metaphor]])
This can be stated in active form. These two phrases have basically the same meaning and emphasize Yahweh being exalted. AT: "now I will exalt myself and show that I deserve for everyone to honor me" (See: [[rc://en/ta/man/translate/figs-activepassive]] and [[rc://en/ta/man/translate/figs-parallelism]])