Jesus painfully came to the knowledge of what it was to be under God's orders. Being named by God a high priest of the order of Melchizedek.

Jesus, our Great High Priest after the order of Melchizedek

And though he was a Son, through the pain which he underwent, the knowledge came to him of what it was to be under God’s orders;
Hebrews 5:8 BBE
Being named by God a high priest of the order of Melchizedek.
Hebrews 5:10 BBE

Heb 5:1 Every high priest who is taken from among men is given his position to take care of the interests of men in those things which have to do with God, so that he may make offerings for sins.

Heb 5:8 And though he was a Son, through the pain which he underwent, the knowledge came to him of what it was to be under God’s orders;
Heb 5:9 And when he had been made complete, he became the giver of eternal salvation to all those who are under his orders;
Heb 5:10 Being named by God a high priest of the order of Melchizedek.