“For this people’s heart is waxed (become) gross, and their ears are dull of hearing, and their eyes they have closed; lest at anytime they should see with their eyes and hear with their ears, and should understand with their heart, and should be converted, and I should heal them” (Matthew 13:15).
        There is a very profound message in this one little verse.  Jesus had begun to teach His disciples using parables, simply put, a parable is:  “an earthly story with a heavenly meaning.”  The Savior gave the reason why He used the parabolic method, it was for the purpose of revealing certain truths to certain people and to conceal these truths from  others, i.e. those who did not have the heart to understand because of unbelief.   He answered and said unto them, “Because it is given unto you to know the mysteries of the kingdom of heaven, but to them it is not given” (Matthew 12:11).  The profound thing I see in Matthew 13:15 is, the heart actually controls or influences just what the eyes see and what the ears hear.  
     Have you ever considered just why it is that some people have such difficulty in seeing clearly just what the Bible says?  Does it concern you that there are certain people who can hear the same Bible message as you and yet have no real understanding when it comes to applying it to themselves in a personal way.  On the other hand, you have both understanding and spiritual application in a personal sense.  The obvious difference is the condition of the heart.  Consider Paul’s word on the subject,  “But as it is written, Eye hath not seen, nor ear heard, neither have entered into the heart of man, the things which God hath prepared for them that love him, but God hath revealed them unto us by His Spirit:  for the Spirit searcheth all things, yea, the deep things of God.” (I Corinthians 2:9,10)  Can it be any clearer than that?
      Jesus said, “For this people’s heart is waxed gross,”  This is a reference to the Nation of Israel and more especially to the religious leaders of that day.  We have already pointed out that the word “waxed” means, “become” but the very next word Jesus uses to describe the heart is the word “gross.”  This word means, “thick, dense, fat, heavy,” which indicates absence of sensitivity.  Jesus is giving them a word from the prophet Isaiah who spoke similar words to a people who continually rebelled and rejected God’s Word to them. 
    The condition of man’s heart differs very little, if any, today.  Our hearts become insensitive, i.e. “thick, heavy” because we will not receive what God has for us in His Word.  Men are constantly forming opinions or trying to assume our intellect will take us where we need to be.  No folks, it is the condition of the heart and only God can change it, because He is the only one who truly knows it. (Jeremiah 17:9,10)
                                                                                                      Pastor H. Preston Parker