Deuteronomy 31:2
1 Then Moses went and spoke these words to all Israel. 2 He said to them, “Today I am 120 years old. I am no longer able to get about, and the Lord has said to me, ‘You will not cross the Jordan.’ 3 As for the Lord your God, he is about to cross over before you; he will destroy these nations before you, and you will dispossess them. As for Joshua, he is about to cross before you just as the Lord has said.
Deuteronomy 34:7
6 He buried him in the valley in the land of Moab near Beth Peor, but no one knows his exact burial place to this very day. 7 Moses was 120 years old when he died, but his eye was not dull nor had his vitality departed. 8 The Israelites mourned for Moses in the rift valley plains of Moab for thirty days; then the days of mourning for Moses ended.
Notes and References
"... the declaration in Deuteronomy 34:7 that Moses died at the age of 120 reveals evidence of implicit theology. It is accorded more detail, namely that he was in good health (“his eyes were not dim, and his vitality had not given way”). Why does Deuteronomy 34:7 emphasize Moses’ good health against the flow of the narrative (see Deuteronomy 31:1–2)? Deuteronomy 34:7 is already brought into connection with Genesis 6:3 by Josephus, which is self-evident for the biblical text because of the motif of the “120” years as a lifespan ... The emphasis on Moses’ health in Deuteronomy 34:7 should accordingly be understood as follows: Moses dies in Deuteronomy 34 for no other reason than that his lifespan had reached the limit set in Genesis 6:3 ..."
Schmid, Konrad Is There Theology in the Hebrew Bible? (p. 95) Eisenbrauns, 2014