While King Jesus was here on planet earth, He always had compassion for those in need. When Jesus was speaking of the heart, He wasn't speaking of that organ that sends the blood rushing through your body, but the mind--the soul. The question is, how do thoughts get to the heart? Through what you see, hear, smell etc. In essence, through the five senses.
King David put it this way: Your word I have hidden in my heart, that I might not sin against You. He also stated this: I will set nothing wicked before my eyes; I hate the work of those who fall away; It shall not cling to me.
Matthew 15:16-20 Psalm 119:11 Psalm 101:3