Isaiah 44:18
They have not known nor understood: for he hath shut their eyes, that they cannot see; and their hearts, that they cannot understand. They have not known nor understood: for he hath shut their eyes, that they cannot see; and their hearts, that they cannot understand.
The chapters around the verse reveal God's purpose for His people. They contrast the true God, the Maker of heaven and earth, with the folly of idols made by human hands. They teach God's people to seek wisdom from Him rather than turning away from Him to depend on finite human wisdom. Idol worship shuts the eyes and the heart, so that worshipers have not known nor understood spiritual truth. Learning to know God through His works helps distinguish the Creator from idols and prepares the mind to receive the spiritual truths of Scripture. This blindness is seen when people seek deliverance from calamity by praying to images of saints, a practice encouraged by priests.