This is unique to Matthew. Jesus said that these Pharisees and Scribes did all their deeds to be seen by other men (πάντα δὲ τὰ ἔργα αὐτῶν ποιοῦσιν πρὸς τὸ θεαθῆναι τοῖς ἀνθρώποις). They broadened their phylacteries (πλατύνουσιν γὰρ τὰ φυλακτήρια αὐτῶν) and enlarged their long fringes or tassels (καὶ μεγαλύνουσιν τὰ κράσπεδα) on their clothes. Thus, they had distinctive garments that they wore. These phylacteries were leather boxes that contained scriptural passages. They would wear them on their forearms or head as indicated in Exodus, chapter 13:9-16. and Deuteronomy, chapter 6:4-9, that was closely tied to the “Shema.” They were to write these biblical sayings of the law on their hands and forehead. On the other hand, the fringes or tassels on the bottom of their clothing was based on Numbers, chapter 15:37-41. They made the tassels on the four corners of their garments, with a blue chord on the fringe of each corner. This was to remember all the commandments of Yahweh, a nice little reminder about their obligations. Ever today, some Jewish groups wear these tassels called the tzitzit. The same command about tassels can be found in Deuteronomy, chapter 22:12. Apparently, the Pharisees may have been the only ones wearing these larger tassels and large prayer boxes.
The Law, the Torah, or the Pentateuch, consisted of first five books that were developed over a number of years, but firmly established around 400 BCE. The five books of the Pentateuch include Genesis, a 10th-5th century BCE writing about the pre-existence of the Israelites, and the particular stories of Abraham, Isaac, Jacob, and Joseph. The Exodus, finished around 450 BCE, recalls the story of Moses and how he led the Israelites out of Egypt for years in the desert. Leviticus and Numbers, worked on between 550-400 BCE, lay out the particular codes, rules and regulations for the Israelites, as well the numbers of people that were involved in the exodus from Egypt. Deuteronomy, developed in the 7th-6th century BCE, told the story of Moses in the wilderness with emphasis on the laws of the heart. This Law or Torah explained the early or pre-history of the Israelites before they entered the promised land. These books also contained all the commands, statutes, or rules for the Israelites after they entered the promised land. All further Jewish developments were based on the Torah or the Law.