4:12- Paul

At the end of Acts Paul has summoned the Jewish leaders of Rome to him (he's under house arrest), From morning to evening he talks to them- some were convinced- others refused to believe- And Paul's passing shot as they are leaving is to quote this verse- and use it to show a hardness of heart that refuses to believe (hear, see), and that “this salvation of God has been sent to the gentiles; they will listen.”

Then along the same lines in Romans 11, What then? Israel failed to obtain what it was seeking. The elect obtained it, but the rest were hardened, as it is written, God gave them a sluggish spirit, eyes that would not see and ears that would not hear, down to this very day.”