And He said, "Go, and tell this people: "Keep on hearing, but do not understand; Keep on seeing, but do not perceive.'
Isaiah 6:9
Surrounding context
6:8 Also I heard the voice of the Lord, saying: "Whom shall I send, And who will go for Us?" Then I said, "Here am I! Send me."
6:9 And He said, "Go, and tell this people: "Keep on hearing, but do not understand; Keep on seeing, but do not perceive.'
6:10 "Make the heart of this people dull, And their ears heavy, And shut their eyes; Lest they see with their eyes, And hear with their ears, And understand with their heart, And return and be healed."