Mark 7:6-7 English Standard Version

And he said to them, “Well did Isaiah prophesy of you hypocrites, as it is written, “‘This people honors me with their lips, but their heart is far from me; in vain do they worship me, teaching as doctrines the commandments of men.’

Isaiah 29:13 English Standard Version

And the Lord said: “Because this people draw near with their mouth and honor me with their lips, while their hearts are far from me, and their fear of me is a commandment taught by men,

That is not a word for word quote but close enough to discover the connection.

The condition of their hearts is identified as the problem in Mark 7 but is expressed as fearing God in Isaiah as a tradition of man. That is not reverence for God which caused their hearts to be far from Him. In Mark 7 it is expressed as a vain attempt, meaning their tradition did not accomplish what God intended for man.

Traditions appear throughout the bible and God does not correct or nullify them if those traditions do not interfere with true worship. God lets the insignificant slide, something that I have had to learn how to do.

Psalm 119:105 Your word is a lamp to my feet and a light to my path.

Psalm 18:28 For it is you who light my lamp; the Lord my God lightens my darkness.

Isaiah 61:1 The Spirit of the Lord God is upon me, because the Lord has anointed me to bring good news to the poor; he has sent me to bind up the brokenhearted, to proclaim liberty to the captives, and the opening of the prison to those who are bound;

John 8:12 Again Jesus spoke to them, saying, “I am the light of the world. Whoever follows me will not walk in darkness, but will have the light of life.”

Plus two more.

Colossians 3:16 Let the word of Christ dwell in you richly, teaching and admonishing one another in all wisdom, singing psalms and hymns and spiritual songs, with thankfulness in your hearts to God.

Hebrews 4:7 again he appoints a certain day, “Today,” saying through David so long afterward, in the words already quoted, “Today, if you hear his voice, do not harden your hearts.”

Let the Spirit of truth tell you how to accomplish this.