John Gill Commentary Numbers 27:22

"And Moses did as Jehovah commanded him; and he took Joshua, and set him before Eleazar the priest, and before all the congregation:" — Numbers 27:22 (ASV)

And Moses did as the Lord commanded him
Being faithful and obedient to him in all things, though ever so contrary to his own private interest and to that of his family:

and he took Joshua and set him before Eleazar the priest, and before
all the congregation ;
as his successor, whom God had named and appointed as such.