Matthew Poole and continuators on Hebrews 5:3

3 And by reason hereof he ought as for the people , so also for himself to offer for sins .

This Connection demonstrates the infirmity of the Legal High Priest: For this their Infirmity, Sins of Ignorance and Error. He was obliged to his Work by the express Law of God, Lev. ch. 1. It is a Rule for what the Priests ought to do, and so is the whole Book to which they are to be punctually obedient, even to sacrifice for particular Sinners in the Church, as they were guilty and brought their Sacrifice, Lev. ch. 4. and for the whole Church of Israel on the Atonement-day, Lev. 16.15 to 34.

He had also his proper Sacrifice for his own Sins commonly, Lev. 4.3. extraordinarily on the day of Atonement annually, Lev. 16.1, 6 to 15. It is not necessary to a Priest to be a Sinner, but it is to be merciful. Adam offered Praiers and Praises to his Creator for himself and Eve in Innocency; but since the Fall our Lord Jesus Christ is the only High-Priest without sin, and yet most merciful, as well as most sensible of the Sins and Miseries of penitent believing Sinners. He offers up the Sacrifice to God truly propitiatory, as his Types did the typical ones, and procured the Pardon which God promised to give upon his so sacrificing to him.

Marginal references: Lev. 9.7. Chap. 7.27.