Tie them: The Lord’s commandments (6:6)were to become part of daily life. They were to shape the thoughts and actions of parents and children, as if they were tied to their bodies.
Later in Jewish practice, some people took this phrase literally. They wrapped leather straps around their forearm and placed small boxes with words from the Torah inside them (see study note on 4:44).
bind them: This phrase was also understood literally in later Judaism. People wore a small box that contained short passages from the Torah. These were called tefillin (Hebrew) or phylacteries (Greek).
These objects reminded people to teach and obey God’s covenant (compare 11:18; Matthew 23:5).