Last words are important.
Deuteronomy presents itself as Moses' last words. It was common in the ancient world to record or to imagine the parting advice of a revered figure. It generated a type of writing called a testament. One of the best known sets of such testaments is the Testaments of the Twelve Patriarchs, where each of the 12 patriarchs offers advice to the next generations and thereby to all following generations. The gospels also use this device.