Because of 41:8,9, our first thoughts are that this Servant we are introduced to in verse 1 must be Israel, but vv.2-4 don’t sound like the Israel we have seen in chs. 40 or 41 (she herself is a bruised reed and smouldering wick, faltering and discouraged), and of course by the end of ch.42 we know it can’t be Israel. But for now the identity of the Servant is enigmatic – more will be revealed in the chapters that follow, and of course the New Testament makes the identification for us (Matt.12:15-21 etc). For now, though, the emphasis is on his task.
The NIV masks the fact that 42:1 begins with the same word as 41:29, which suggests a link: the Servant is the answer to the barrenness and emptiness described at the end of ch.41. But in vv.1-4 the key word to understand the task he’s been given is the word “justice”. The word refers to the righting of wrongs, but see the discussion in Jackman’s notes. Motyer suggests that here “justice is the Lord’s truth and the truth about the Lord”, so the Servant’s task is to bring the truth of God to the world. Notice the scope of his work – that it is for the whole world is mentioned a number of times. And notice the manner in which he goes about it – not in a flashy way, but quietly, gently and mercifully, and persistently. That he should “be a covenant for the people” means that he will be the means by which people (ie Jew and Gentile) will come into covenant relationship with the Lord.
In response to the Servant’s work, in vv.10ff the world is called to praise God, who at last will bring judgement (v.15) and rescue (v.16). The invitation of v.18 though is seemingly stymied because those who should have been the servant through whom this would all be accomplished are shown themselves to be as much in need of the Servant’s ministry as anyone. They have had God’s word but ignored it and disobeyed it, for which they have been duly punished.