John Calvin Commentary Hebrews 2:3

"how shall we escape, if we neglect so great a salvation? which having at the first been spoken through the Lord, was confirmed unto us by them that heard;" — Hebrews 2:3 (ASV)

If we neglect so great a salvation, etc. Not only the rejection of the Gospel, but also its neglect, deserves the heaviest punishment, and that on account of the greatness of the grace which it offers. For this reason, he says, so great a salvation. God indeed intends for His gifts to be valued by us according to their worth. Then the more precious they are, the more shameful is our ingratitude when we do not value them. In short, in proportion to the greatness of Christ will be the severity of God’s vengeance on all who despise His Gospel.

And observe that the word "salvation" is used here metonymically for the doctrine of salvation. For as the Lord does not intend for people to be saved in any other way than by the Gospel, so when the Gospel is neglected, the whole salvation of God is rejected; for it is God’s power unto salvation to those who believe (Romans 1:16). Therefore, whoever seeks salvation in any other way seeks to attain it by a power other than God’s, which is evidence of extreme madness. But this high praise is not only a commendation of the Gospel but is also a wonderful support to our faith, for it is a testimony that the word is by no means unprofitable, but that a sure salvation is conveyed by it.

Which at first began, etc. Here he contrasts the Son of God, the first herald of the Gospel, with angels, and also anticipates what was necessary to remove a doubt that might have crept into the minds of many. For they had not been taught by Christ Himself, whom the majority had never seen. If, then, they regarded only the man by whose ministry they had been led to the faith, they might have undervalued what they had learned from him. Therefore, the Apostle reminded them that the doctrine which had been delivered to them by others nevertheless proceeded from Christ, for he says that those who had faithfully declared what had been committed to them by Christ had been His disciples. He therefore uses the word, was confirmed, as if he were saying that it was not a random report, without any author or from witnesses of questionable credibility, but a report that was confirmed by men of importance and authority.

Moreover, this passage indicates that this epistle was not written by Paul; for he did not usually speak so humbly of himself as to confess that he was one of the Apostles’ disciples. Nor did he speak in this manner from ambition, but because wicked men, under such a pretext, attempted to detract from the authority of his doctrine. It therefore appears evident that it was not Paul who wrote that he had received the Gospel by hearing and not by revelation.