Textual analysis: As is typical of Isaiah, we have a change in the locutor with no hint other than context. Up through the end of verse 8, the Lord was speaking. One would logically expect the same speaker to begin the exhortation "awake, awake," but this is not the case. Clearly when the Lord is addressed we learn that it is now Israel who speaks.
The text now creates a contrast between the position of the Lord and that of Israel. In verses 1-8 the Lord has been emphasizing the continuity of his promise, and the eventuality of his victory. In verses 9-11 Israel voices a more narrow picture. While God's vision is long range, Israel's is short term. While God proclaims the eventual permanence of his work (verse 6), Israel exhorts the Lord to a more active participation in the present. Note the invocation to awake directed at the Lord.
Israel contrasts God's vast vision with their immediate need, reminding the Lord of his involvement with Israel in days past, and the invocation to do so now. They want the awakening not of the spiritual food, but of the political intervention. It is the "arm of the Lord" that is invoked. The images are military, not spiritual. Israel asks for assistance in the current world, and asks for a rather temporal assistance.
Literary note: Concerning Rahab:
"... the sea monster (Rahab) mentioned in v. 9 probably represents Satan (see... Isaiah 17:1), but might also represent Egypt. Perhaps Isaiah is reminding the people of the Lord's victory over Satan as well as his miracles in Egypt." (Ludlow 1982, p. 428).