Deuteronomy 6: 6 These commandments that I give you today are to be upon your hearts. 7 Impress them on your children. Talk about them when you sit at home and when you walk along the road, when you lie down and when you get up. 8 Tie them as symbols on your hands and bind them on your foreheads.
Did the above in any way mean we are to tie physical objects (Tefillin and Tekhelet) to our heads and hands? The truth is: We just don't know for sure.
While there are no scriptures to verify that Yeshua wore tefillin (there is some argument that the PRECISE final form of rabbinic traditional tekhlet and tefillin developed over time and finalized in the Middle Ages), it would not be correct to say that no form of these items were worn in Yeshua's time, either by Him or his followers....
Tefillin are traditional prayer objects that were an invention of the Pharisees, which was later picked up by the Rabbis. The Gospels reveal they were worn all day long by the Pharisees to give the impression that they were pious men, constantly praying.
Matthew 23: 5. And they do all their deeds that they might be seen by the sons of men. For they widen their Tefillin  and lengthen the Tekhelet  of their robes. (Aramaic English New Testament)
 Leather box/straps containing Bible verses that traditional observant Jews bind on their arms and foreheads during daily prayer, except on Shabbat (Deut. 6:8 (Paul Younan translation)).
 The "ribbon of blue" of the "tzitzit" (fringes), as commanded in Num. 15:38. "Tekhelet" can also refer to tzitzit, or even the whole prayer shawl/talit. (Paul Younan translation)
So, let's think about this, logically:
Why would YHWH tell us to "tie them as symbols on your hands and bind them on your foreheads"? When these words were given, man certainly did not understand the reason. The Orthodox Jews - hundreds, if not thousands of years ago - took this verse literally and came up with actual, physical ways to comply with this command. They wrote down the words of YHWH on pieces of parchment, inserted them in little boxes (called Tefillin) attached to bands, and literally tied them to their hands and foreheads.
But, is this really what YHWH meant for us to do? Let's examine it from both, a Biblical and a scientific perspective.
Today, science has a pretty good working knowledge of all things physical. This includes an excellent working knowledge of the human brain. Unfortunately, scientists tend to get wrapped up in their particular mindsets and often think they have "the answer" to nearly every question - but that's fodder for another article....
The human brain is described today by scientists as consisting of several parts that control different functions. You are probably familiar with the terms "cerebrum" or "cerebral cortex", "cerebellum", and "brain stem".
The cerebral cortex is the largest part consisting of those two roughly symmetrical, "corrugated-looking" or "folded" hemispheres. Though far more complicated than can be covered here, the cerebral cortex, having much to do with the physical and mental functions of our bodies, is further divided into areas called the "frontal lobe", "parietal lobe", "occipital lobe", and the "temporal lobe". Scientists have determined that these cerebral cortex lobes correspond to the following functions:
||Motor control and cognitive activities, such as planning,
making decisions, setting goals, speech, and purposeful behavior
||Sensory processes, spatial interpretation, attention, and language comprehension
||Processes visual information and communicates with the parietal and temporal lobes
||Auditory perception, language comprehension, and visual recognition
The area at the very front of the frontal lobe is called the "Prefrontal Cortex". Let's look at a study on the prefrontal cortex in a February 2003 article in Nature Reviews on the human brain by Jacqueline Wood and Jordan Grafman: "Human Prefrontal Cortex: Processing and Representational Perspectives".
Grafman and Wood start out by saying "Although it is clear that the PFC [Prefrontal Cortex] is important for higher cognitive skills, particularly in humans, how it achieves these functions is unknown." Interestingly, throughout the remainder of the article, Grafman and Wood speak casually about how the human brain "evolved" into its capability of higher cognitive skills. You see, for many - if not most - scientists, "evolution" explains without them having to actually come up with an explanation....
Grafman and Wood go on to say the PFC has two main areas that deal not only with each other, but with other parts of the brain. One part of the PFC, (the "ventromedial" region), is associated with other parts of the brain that deal with emotional processing, memory, and visual information; and the other part of the PFC, (the "dorsolateral" region), is associated with areas of the brain dealing with motor control, mood and emotions (cingulate cortex), and the sensory processing done in the parietal cortex.
Specifically: "The ventromedial PFC is well suited to support functions involving the integration of information about emotion, memory, and environmental stimuli, and the dorsolateral PFC to support the regulation of behavior and control of responses to environmental stimuli." After describing the types of cells in the PFC and how the neurons in the PFC can act differently than in other parts of the brain, they say: "This is one structural explanation for the PFC's ability to integrate inputs from many sources and to implement more abstract behaviors."
In other words, the prefrontal cortex is where you make decisions to take action on a thought. The prefrontal cortex handles your behavior! Frontal lobe is the part of the brain that is last to reach maturity. Reasoning and moral judgment is carried out by the frontal lobe. Every human mind is as unique as a fingerprint. Every thought is uniquely processed in each different human brain. The thought comes into the frontal lobe and then goes through the unique process of order and duration in the different parts of the brain. The frontal lobe determines how to interpret the thought according to the training the frontal lobe has been taught. The thought "goes around" through the brain and is then "bound" by the frontal lobe into what it believes the thought to be. Frontlet according to Strong's #2903 is; towphaphah, from an unused root meaning to go around or bind. Can the Word of God be anything but absolutely correct?
Now consider this: Thousands of years before man developed the modern sciences and determined what parts of the brain are responsible for the various human behaviors and activities, YHWH told man to keep His words "on your forehead".
Touch your forehead. Go ahead. No one is watching. Just a fraction of an inch beyond your fingertips is the PREFRONTAL CORTEX. God told us to keep His word there. Keeping His word there keeps us from processing worldly desires and events (i.e., evil) and acting on it. If we keep God's word in our prefrontal cortex, we are less likely to commit sin.
And there you have the reason for Deuteronomy 6:6-8! Talking about God's word keeps His commandments on our foreheads, on our prefrontal cortex, and thus, keeps us from sin.
Exodus 13 below shows proof positive that it's not a literal binding on our hands and forehead, as we see YHWH reiterating the importance of His Passover and what His people are to DO and REMEMBER on/about that particular Holy Convocation:
Exodus 13: 1 ADONAI said to Moshe, 2 "Set aside for me all the firstborn. Whatever is first from the womb among the people of Isra'el, both of humans and of animals, belongs to me." 3 Moshe said to the people, "Remember this day, on which you left Egypt, the abode of slavery; because ADONAI, by the strength of his hand, has brought you out of this place. Do not eat hametz. 4 You are leaving today, in the month of Aviv. 5 When ADONAI brings you into the land of the Kena'ani, Hitti, Emori, Hivi and Y'vusi, which he swore to your ancestors to give you, a land flowing with milk and honey, you are to observe this ceremony in this month. 6 For seven days you are to eat matzah, and the seventh day is to be a festival for ADONAI. 7 Matzah is to be eaten throughout the seven days; neither hametz nor leavening agents are to be seen with you throughout your territory. 8 On that day you are to tell your son, 'It is because of what ADONAI did for me when I left Egypt.' 9 Moreover, it will serve you as a sign on your hand and as a reminder between your eyes, so that ADONAI's Torah may be on your lips; because with a strong hand ADONAI brought you out of Egypt..."
As you can deduce from the above, it's all about DOING so that we can better REMEMBER! "Tie them as symbols on your hands," does not mean we are literally attach anything to, or write down YHWH's word on our hands!
Consider this: We decide what to do with our brains. God asked us to keep his word in our prefrontal cortex so we would not sin. When we sin, how do we typically commit those sins? With our hands! A thief does not steal with his ear. An angry man does not strike another with his hair. A man does not kill another with his nose. A forger does not fake a signature (typically) with his foot.
In the majority of cases, we commit our sins with our hands. Keeping God's word "on our hands" would mean that we proceed through life not allowing our hands to commit a sin.
What marvelous words in Deuteronomy 6:6-8! It is truly a wonder why so many people think the Torah, God's original teaching and instruction, has been "done away with". His words are so true and so powerful!
YHWH's Torah was given to us long before science learned to describe the very reasons for it!