Audio commentary on this verse

Note 6 at Rom. 9:33: Those who are offended at Jesus are the ones who are trusting in themselves. They feel they will be accepted with God because they are holy enough on their own. It is humbling to admit that all of of our righteousness is as filthy rags (Isa. 64:6). This is why the religious people have always been the persecutors of true Christians (see note 6 at Mk. 15:10, p. 524).

Note 7 at Rom. 9:33: This quotation does not appear in the Old Testament in these exact words. It is most probable that Paul is quoting the last part of Isaiah 28:16 (see O.T. Scripture cited for v. 33). If so, Paul substituted the words "be ashamed" for Isaiah's words "make haste." In the context of war, making haste is descriptive of a person who has been shamed in battle.