Green denies that the parable of the banquet in Luke 14:16ff is about the Messianic banquet. It suggests that God at one time did NOT want the poor to His banquet, but included them as a kind of afterthought; this not only is unflattering to God, but goes contrary to Luke’s theology, which sees in Jesus’ open invitation to the table a fulfillment of promises made to Abraham. He also denies that the story allegorizes God’s turn from Jews to Gentiles.
I don’t find these objections persuasive. Surely the allegory ought not be pressed to suggest that God came upon the idea of including the poor and crippled as a “second best” response to the original invitation. But the prophetic literature of Israel is full of this kind of thing: Yahweh stretches out His arms to a disobedient people, who refuse; so Yahweh turns to Gentiles. That’s precisely what’s happening here, and the parable functions perfectly as an allegory of Israel’s history and of Jesus’ recapitulation of that history.