The Gospels attest to the fact that Jesus had tassels on the four corners of his outer robe (Matt. 9:20; 14:36; Mark 6:56; Luke 8:44). Although there is no explicit evidence in the Gospels, we have reason to suggest that he also may have worn phylacteries.
The original understanding of the third commandment, “You shall not take the name of the LORD your God in vain” (Exod. 20:7), was that one must keep one’s vows when swearing by God’s name. Israel’s ancient sages eventually came to interpret this commandment to mean using the LORD’s name lightly or frivolously. To avoid the risk of employing the divine name irreverently, the sages ruled that one should not utter it at all.