Are you saying that only the Ten Commandments are found in
Deuteronomy 6:4?
Is the "603" number why you keep bringing up the Pharisees? It's in the thread title. I'm just using it as shorthand in this thread for "instructions other than the Ten Commandments."
So, if we consider what commandments from the law of Moses we are to keep today, do any of them come from the instructions other than the Ten Commandments?
Why would a person want to separate verse 4 from the context in which it was said? Notice the conjunction and as the first word in verse 5 which signifies verse 4 is a part of a much larger thought.
Deuteronomy 6: 4 Hear, O Israel: The Lord our God is one Lord:
5 And thou shalt love the Lord thy God with all thine heart, and with all thy soul, and with all thy might.
6 And these words, which I command thee this day, shall be in thine heart:
7 And thou shalt teach them diligently unto thy children, and shalt talk of them when thou sittest in thine house, and when thou walkest by the way, and when thou liest down, and when thou risest up.*n2
8 And thou shalt bind them for a sign upon thine hand, and they shall be as frontlets between thine eyes.
9 And thou shalt write them upon the posts of thy house, and on thy gates.
10 And it shall be, when the Lord thy God shall have brought thee into the land which he sware unto thy fathers, to Abraham, to Isaac, and to Jacob, to give thee great and goodly cities, which thou buildedst not,
11 And houses full of all good things, which thou filledst not, and wells digged, which thou diggedst not, vineyards and olive trees, which thou plantedst not; when thou shalt have eaten and be full;
12 Then beware lest thou forget the Lord, which brought thee forth out of the land of Egypt, from the house of bondage.*n3
13 Thou shalt fear the Lord thy God, and serve him, and shalt swear by his name.
You're becoming just like a Pharisee when you're implying the instructions as to frontlets and hands and sign posts should be carried out literally. The continuation of the passage makes this obvious. The message is to keep God in the forefront of our minds in all we think, do, and say. as verse 7 plainly says. The Pharisees did exactly what you're implying and they lost sight of God completely as they made them the physical objects the point.
Jesus made the same point.
Matthew 23: 1 Then spake Jesus to the multitude, and to his disciples,
2 Saying, The scribes and the Pharisees sit in Moses’ seat:
3 All therefore whatsoever they bid you observe, that observe and do; but do not ye after their works: for they say, and do not.
4 For they bind heavy burdens and grievous to be borne, and lay them on men’s shoulders; but they themselves will not move them with one of their fingers.
5 But all their works they do for to be seen of men: they make broad their phylacteries, and enlarge the borders of their garments,
6 And love the uppermost rooms at feasts, and the chief seats in the synagogues,
7 And greetings in the markets, and to be called of men, Rabbi, Rabbi.
8 But be not ye called Rabbi: for one is your Master, even Christ; and all ye are brethren.