From #1550-
Heb 3-
16 Who were they who heard and rebelled? Were they not all those Moses led out of Egypt?
17 And with whom was he angry for forty years? Was it not with those who sinned, whose bodies perished in the wilderness?
18 And to whom did God swear that they would never enter his rest if not to those who disobeyed?
19 So we see that they were not able to enter, because of their unbelief.
v.19 applies to Moses just as much as to the rest.
Numbers 14:29 - In this wilderness your bodies will fall—every one of you twenty years old or more who was counted in the census and who has grumbled against me.
Numbers 20:12 - But the LORD said to Moses and Aaron, “Because you did not trust in me enough to honor me as holy in the sight of the Israelites, you will not bring this community into the land I give them.”
Deut 32:51 - This is because both of you broke faith with me in the presence of the Israelites at the waters of Meribah Kadesh in the Desert of Zin and because you did not uphold my holiness among the Israelites. Moses' and Aaron's indictment!
Moses didn't enter the land because of his "unbelief", just as Heb 3:19 says.