From one of Thomas Goodwin’s treatises:
“The office of high priesthood is altogether an office of grace, and I may call it the pardon office, set up and erected by God in heaven, and Christ is appointed the Lord and Master of it.
“And, as his kingly office is an office of power and dominion, and his prophetical office is an office of knowledge and wisdom, so his priestly office is an office of grace and mercy. The high priest’s office did properly deal in nothing else. If there had not been a mercy-seat in the Holy of Holies, the high priest had not at all been appointed to have gone into it. It was mercy, and reconciliation, and atonement for sinners, that he was to treat about, and officiate for, at the throne of grace. He had otherwise had no work, nor anything to do when he came into the Most Holy place.”
(This observation is drawn from Hebrews 5:2, where the high priest is specified as someone “who can have compassion on the ignorant, and on them that are out of the way, for that he himself also is compassed with infirmity.”)
Thomas Goodwin, The Heart of Christ in Heaven. First published 1645.
Its full title is: “The heart of Christ in heaven towards sinners on earth; or, a treatise demonstrating the gracious disposition and tender affection of Christ, in his human nature now in glory, unto his members, under all sorts of infirmities, either of sin or misery.”