The phylacteries refer to the command of the Lord given to Moses when he said, “You shall therefore lay up these words of mine in your heart and in your soul, and you shall bind them as a sign on your hand, and they shall be as frontlets between your eyes” (Deuteronomy 11:18 ESV).
|Modern-day tefillin (black) compared with ancient tefillin from Qumran|
The head tefillin has four small compartments, each containing a scroll with one of the four passages of scripture mentioned, and is bound to the head to symbolize that the law of God is always on the forefront of our minds. “In the scriptures ... the forehead represents what a person’s thoughts dwell on and therefore what he loves or desires. ... For the same reason, the Mosaic high priest wore an engraved gold signet on his forehead that read ‘Holiness to the Lord’ (see Exodus 28:36-38). This was a reminder that his thoughts should always be holy, with the result that his actions would follow suit.” 
|Modern-day tefillin showing the scroll compartments (head-left, arm-right)|
The fringes or ‘borders of their garments’ or tzitzit in Hebrew, refers to blue tassels tied to the four corners of their garments and were meant to be a constant reminder of God’s commandments. The Lord said unto Moses, “Speak unto the children of Israel, and bid them that they make them fringes in the borders of their garments throughout their generations, ... that ye may look upon it, and remember all the commandments of the Lord” (Numbers 15:38-39).
It is significant to note that in condemning the Pharisees for their tefillin and tzitzit, the Lord does NOT condemn them for wearing them, or for even having larger tefillin or longer tzitzit than others! The reason he condemns the Pharisees is because they wear these “to be seen of men” (see Matthew 23:5)
|Replica of a Dead Sea Scrolls tefillin compared to an ancient coin|
Second, on a more personal level, we must be careful about the reasons we obey the laws of God, especially the more outward and noticeable laws, such as church attendance, honoring the Sabbath, or dress and grooming standards. Do we obey the laws of the Lord only so that others can see how good we are, or do we obey them because we truly have God’s law bound to our heart and mind?
I can’t help but wonder if God specifically gave us some of these more “outward” laws so that we can prove to Him that the law is actually more inward. To prove that the law is deeply rooted into our souls, and that we show our religion not just by what we wear or by how we look, but by how we love, serve and care about others. For this is the true purpose behind the law.
 Jesus Christ and the World of the New Testament, page 48
 The Lost Language of Symbolism, page 39 (see Forehead)
 The Lost Language of Symbolism, page 45-47 (see Head and Heart)