What does Matthew 23:5 mean?

The scribes and Pharisees, Israel's religious leaders, fail to practice what they preach. Jesus is describing the hypocrisy behind their very religious public appearance (Matthew 23:1–4).

Here, Jesus addresses their motives. They may do what is right or religious, according to their own interpretations, but they do so to be seen by others. They want approval and recognition of the people: to be heralded as good and religious men. One way they exhibit this is by their outward appearance. These included religious emblems such as phylacteries and fringes.

Phylacteries are known today as "tefillin." They are small leather boxes containing pieces of parchment with Scripture written on them. The phylactery boxes were strapped to the left arm or forehead in literal obedience to Deuteronomy 11:18. The Scriptures inside were from Exodus 13 and Deuteronomy 6.

Fringes, or tassels, are dangling bits of thread, with a blue cord, attached to the four corners of a Jewish man's garment in obedience to Numbers 15:38–39: "Tell them to make tassels on the corners of their garments throughout their generations, and to put a cord of blue on the tassel of each corner. And it shall be a tassel for you to look at and remember all the commandments of the Lord, to do them."

It's important to note that Jesus does not condemn the wearing of phylacteries or fringes. The objects are not wrong, and neither is their use. Rather, He calls out religious leaders for making an excessive show of those objects: wearing large, broad phylacteries and extended fringes so everyone will notice them. Their intent is not primarily to honor God; it's to get credit from other men for being extra religious and good. They had lost sight of the proper motive for these religious objects: a reminder of the law.