Bro. Stone's argument in the previous three paragraphs is both naive and absolutely wrong. The verse says he obtained redemption through his blood. Bro. Stone says we can't know what the expression "by his blood" means. That it could mean several things. Well, perhaps if Paul was speaking with no supporting context, this would be true. But for nine chapters so far, and also for the rest of the book, Paul is only talking about one subject: how the law of Moses was a type of Christ. So when Paul says that he obtained eternal redemption through his blood, the expression is understood in harmony with the Mosaic law.
If we say that something was redeemed by blood under the Mosaic law, what do we mean? There is no ambiguity there. We understand that to mean atonement. That is what blood shedding under the Mosaic Law was for. As Lev. 17:11 says: "For the life of the flesh is in the blood: and I have given it to you upon the altar to make an atonement for your souls: for it is the blood that maketh an atonement for the soul."
In this same chapter of Hebrews, Paul takes from the 19th verse to the 23rd verse to explain that by the law, almost all things were purged with blood. Now he wasn't talking about the obedience of the High Priest in making the sacrifice. He was talking about the principles of redemption which were involved in the blood shedding sacrifice on account of sin. In the 23rd verse, he equates all this to Christ. HEB 9:23 "It was therefore necessary that the patterns of things in the heavens should be purified with these; but the heavenly things themselves with better sacrifices than these." The heavenly things themselves, was that which the patterns were a type of. The heavenly things were Christ. The pattern was purged in symbol, with the blood of bulls and goats, which could not take away sin. But the Heavenlies themselves, were purged with the better sacrifice, the blood of Christ.
So to say that we can't know what Paul's expression really means, and therefore we are at liberty to put some idea pulled out of the air here, is to completely ignore context. The aspect of obedience was of fundamental importance. And of course Jesus had no moral iniquity to be redeemed from. But in order to say that this verse does not teach that Christ himself was redeemed on account of his own blood shedding sacrifice, which was an atonement for sin; is to ignore the verse, the words, and the context.