The reading is from St. Paul's Letter to the Romans 11:2-12

Brethren, do you not know what the scripture says of Elijah, how he pleads with God against Israel? "Lord, they have killed thy prophets, they have demolished thy altars, and I alone am left, and they seek my life." But what is God's reply to him? "I have kept for myself seven thousand men who have not bowed the knee to Baal." So too at the present time there is a remnant, chosen by grace. But if it is by grace, it is no longer on the basis of works; otherwise grace would no longer be grace. What then? Israel failed to obtain what it sought. The elect obtained it, but the rest were hardened, as it is written, "God gave them a spirit of stupor, eyes that should not see and ears that should not hear, down to this very day." And David says, "Let their table become a snare and a trap, a pitfall and a retribution for them; let their eyes be darkened so that they cannot see, and bend their backs for ever." So I ask, have they stumbled so as to fall? By no means! But through their trespass salvation has come to the Gentiles, so as to make Israel jealous. Now if their trespass means riches for the world, and if their failure means riches for the Gentiles, how much more will their full inclusion mean?