Old Testament readings use the Septuagint , the Scripture the apostles quoted. Masoretic numbering shown for reference.Learn why
WEB

Isaiah 51:9

Awake, awake, put on strength, arm of Yahweh! Awake, as in the days of old, the generations of ancient times. Isn’t it you who cut Rahab in pieces, who pierced the monster?

Read in other translations