“The rebellion referred to in verse 2 is now specified: worship had been divorced from justice, and the fatherless and the widow had become the chief victims (v.17). Such disregard for justice was a fundamental violation of the Sinai covenant for which no amount of cultic observance [ie. sacrifices at the temple, etc.] could compensate. The exodus itself had flowed out of God’s concern for the oppressed, and from the very beginning he had demanded that his people should have a special conern for the poor and defenceless among them. Furthermore, it is a requirement which has been intensified rather than diminished under the new covenant within which we ourselves now stand. If proof is required we need look no further than Jesus’ parable of the good Samaritan, or James’ description of ‘religion thatGod our Father accepts as pure and faultless’. The cross places us under a far greater obligation to love than the exodus ever could.”
B.G.Webb, The Message of Isaiah (Leicester: IVP, 1996), 43.