Matthew Poole and continuators on Hebrews 5:8

8 Though he were a son, yet learned he obedience by the things which he suffered .

He fulfilled his Type in the end; for tho he were God the Son incarnate in a nearer and more excellent Relation to the Father, than any Angel, or any High-Priest among Men His Types, being all Servants to his Father and him; God's Son by eternal Generation as to his Deity, by Conception from the Holy Ghost by the Virgin as to his Humanity, who for his worth might have been exempted from such Burdens, yet did God teach him (not as if he wanted it at any Time) by what he imposed and commanded him, and he learnt by what he did agree and covenant to perform Active Obedience to God's Will, fulfilling all Righteousness, being for his Person, and doing for his Work to a Tittle what God required from him, but especially Passive Obedience, by his experience knowing what it meant, freely subjecting himself to his State of Humiliation, Phil. 2.6, 7, 8. enduring all the Indignities and Sufferings for Sinners from his Birth to his Death, even the most vile and cursed. This the Father injoined and commanded him, and he did obey it; read Isa. 53. He who offered Prayers for himself, as an High-Priest offered himself a Sacrifice for us, as ours. By this did he finish his Father's Will intirely, experimentally, feelingly, knowing how difficult Patience under the Cross is, and how to pity us under all our Sufferings.