It is Moshe's last day on earth, and as he prepares to part from his beloved people, he also relays to Israel the final two commandments of Torah:
1. The once-every-seven-years Hakhel gathering of all Israel for the reading of the entire Torah by the king of Israel in the Holy Temple, and
2. The writing of a complete sefer Torah by each and every member of the nation of Israel.
These two seemingly unrelated commandments together are part of an important message concerning the nature and potential of Shabbat Shuva (the Sabbath of Repentance) that occurs every year during the 'Ten Days of Repentance' between Rosh Hashanah and Yom Kippur.