Of how much sorer punishment, suppose ye, shall he be thought worthy, who hath trodden under foot the Son of God, and hath counted the blood of the covenant, wherewith he was sanctified, an unholy thing, and hath done despite unto the Spirit of grace? Of how much sorer punishment - Such offenses were trifling in comparison of this, and in justice the punishment should be proportioned to the offense.
Trodden under foot the Son of God - Treated him with the utmost contempt and blasphemy.
The blood of the covenant - an unholy thing - The blood of the covenant means here the sacrificial death of Christ, by which the new covenant between God and man was ratified, sealed, and confirmed. And counting this unholy, or common, κοινον, intimates that they expected nothing from it in a sacrificial or atoning way. How near to those persons, and how near to their destruction, do they come in the present day who reject the atoning blood, and say, "that they expect no more benefit from the blood of Christ than they do from that of a cow or a sheep!" Is not this precisely the crime of which the apostle speaks here, and to which he tells us God would show no mercy?
Despite unto the Spirit of grace? - Hath insulted the Spirit of grace. The apostle means the Holy Spirit, whose gifts were bestowed in the first age on believers for the confirmation of the Gospel. See Hebrews 6:4-6. Wherefore, if one apostatized in the first age, after having been witness to these miraculous gifts, much more after having possessed them himself, he must, like the scribes and Pharisees, have ascribed them to evil spirits; than which a greater indignity could not be done to the Spirit of God. Macknight. This is properly the sin against the Holy Ghost, which has no forgiveness.