Jesus quoted this Scripture in Isaiah when He called the Pharisees and Teachers of the Law hypocrites. Paul exhorted the Church in Colossians 2:20-23 of the same thing. Human regulations, commands, and teachings were overtaking and overshadowing God’s Word, and that they had the “appearance” of wisdom but lacked any true value because they were all based on man’s understanding and not Scripture. This vain worship spoken of by Isaiah here was only empty, insincere words and rituals…that God considered unacceptable. For true worship of God has to be according to His Will revealed by Scripture…not some religious exercises designed by presumptuous humans beings.