Isaiah 44:9
They that make a graven image are all of them vanity; and their delectable things shall not profit; and they are their own witnesses; they see not, nor know; that they may be ashamed. They that make a graven image are all of them vanity; and their delectable things shall not profit; and they are their own witnesses; they see not, nor know; that they may be ashamed.
Isaiah 44:9 stands in Isaiah 41-45, where God very fully reveals His purpose for His people, contrasting His own wisdom and saving power with human folly. Those chapters are to be prayerfully studied as God's revelation of His purpose. In that setting the verse warns against turning away from God and His wisdom to look to finite man, finite human beings, and finite human wisdom.
Those who make a graven image produce something worthless, and their prized and delectable objects bring no profit, benefit, or advantage to those who make and trust in them. The makers fashion and worship objects from things God Himself provided, while denying the Creator and giving Him no thanks. The makers are their own witnesses against themselves, for they see not and know not, they do not see or understand, and this blindness and ignorance exposes their folly and leaves them ashamed.
The verse contrasts these human-made objects with the true God as Maker of heaven and earth. Learning about God through His works helps people recognize that difference and prepares them to receive the spiritual truths of Scripture. Such idolatry corrupts its worshipers and turns even beautiful groves and trees into places devoted to false worship.
This futility was shown when people carried images of saints and prayed to them for deliverance during a cholera outbreak, yet the images could not save them from the plague. The verse also reaches beyond images of wood or stone, for false doctrines and theories become idols when they misrepresent God and replace the living God with a false conception of Him. Such intellectual and cultural substitutes deny God's authority and make created nature an object of worship instead of its Creator.