Isaiah 51:9

Israel’s call for God to awake assumes that He had not been active in helping His people recently. Isaiah, speaking for the Israelites, described the Lord’s delivering power in action for His people as His "arm" (cf. Isaiah 51:5; Isaiah 53:1). His arm had defeated the Egyptians and Pharaoh in the Exodus in the past, here described respectively as Rahab (lit. proud one, cf. Isaiah 30:7; Psalms 87:4) and the dragon (cf. Ezekiel 29:3). Rahab and the dragon were also part of the mythological lore of the ancient Near East. By using these names, Isaiah was undoubtedly stressing Yahweh’s ability to overcome all the pagan gods and every other power opposing Israel’s salvation.