How does Deuteronomy 1:3 emphasize Moses' obedience to God's commands?

“‘In the fortieth year, on the first day of the eleventh month, Moses spoke to the Israelites according to all that the LORD had commanded him regarding them.’ (Deuteronomy 1:3) — The verse underscores Moses’ obedience by specifying that he relayed every word God gave him, at the precise time God appointed, without adding to or subtracting from the divine command.”