John Calvin Commentary 2 Timothy 4:17

"But the Lord stood by me, and strengthened me; that through me the message might me fully proclaimed, and that all the Gentiles might hear: and I was delivered out of the mouth of the lion." — 2 Timothy 4:17 (ASV)

But the Lord assisted me. He adds this to remove the offense that he saw might arise from that shameful desertion of his cause. Though the church at Rome had failed to perform its duty, he affirms that the gospel had suffered no loss because of it. Leaning on heavenly power, he himself was fully able to bear the whole burden. He was so far from being discouraged by the fear that gripped everyone, that it only became more evident that the grace of God does not need help from any other source.

He does not boast of his courage but gives thanks to the Lord that, when reduced to extreme difficulties, he did not give way or lose heart under so dangerous a temptation. He therefore acknowledges that he was supported by the Lord's arm and is satisfied with this: that the inward grace of God served as a shield to defend him against every assault. He assigns the reason:

That the proclamation might be confirmed. He employs the word "proclamation" to denote the office of publishing the gospel among the Gentiles, which was especially assigned to him, for the preaching of others did not so much resemble a proclamation because it was confined to the Jews. And he uses this word with good reason in many passages. It was a significant confirmation of his ministry that, when the whole world foamed with madness against him and, on the other hand, all human assistance failed him, he still remained unshaken. Thus he gave a practical demonstration that his apostleship was from Christ.

He now describes the manner of the confirmation: that all the Gentiles might hear that the Lord had so powerfully assisted him. For from this event they could infer that both their own calling and Paul's were from the Lord.

And I was delivered out of the mouth of the lion. By the word "lion," many suppose that he means Nero. For my part, I am more inclined to think that he uses this expression to denote danger in general, as if he had said, "out of a blazing fire," or "out of the jaws of death." He means that he escaped only through wonderful assistance from God, as the danger was so great that without it, he would have been immediately swallowed up.