Numbers 15:39 and it shall be to you for a fringe, that you may look on it, and remember all the commandments of Yahweh, and do them; and that you not follow after your own heart and your own eyes, after which you use to play the prostitute;  (WEB)

and it shall be unto you for a fringe, that ye may look upon it, and remember all the commandments of Jehovah, and do them; and that ye follow not after your own heart and your own eyes, after which ye use to play the harlot;  (ASV)

So that, looking on these ornaments, you may keep in mind the orders of the Lord and do them; and not be guided by the desires of your hearts and eyes, through which you have been untrue to me:  (BBE)

and it shall be unto you for a tassel, that ye may look upon it, and remember all the commandments of Jehovah, and do them; and that ye seek not after the lusts of your own heart and your own eyes, after which ye go a whoring;  (DBY)

And it shall be unto you for a fringe, that ye may look upon it, and remember all the commandments of the LORD, and do them; and that ye seek not after your own heart and your own eyes, after which ye use to go a whoring:  (KJV)

And it shall be to you for a fringe, that ye may look upon it, and remember all the commandments of the LORD, and do them; and that ye seek not after your own heart and your own eyes, after which ye use to go astray:  (WBS)

And it shall be unto you for a fringe, that ye may look upon it, and remember all the commandments of the LORD, and do them; and that ye go not about after your own heart and your own eyes, after which ye use to go astray;  (JPS)

and it hath been to you for a fringe, and ye have seen it, and have remembered all the commands of Jehovah, and have done them, and ye search not after your heart, and after your eyes, after which ye are going a-whoring;   (YLT)

This refers to idolatry of seeking your own inner thoughts rather than God.  It even includes observation.  Yet, modernist and post-modernist science thinks that observation is the ultimate when combined with rationalism and certain rationalized presuppositions.  That very thought is idolatry, a sin against the First Commandment.  And every test shows us that our ability to observe is greatly limited and flawed.  The human mind simply filters out what it cannot accept.