Matthew 16:18

On this rock — Alluding to his name, which signifies a rock, namely, the faith which thou hast now professed; I will build my Church — But perhaps when our Lord uttered these words, he pointed to himself, in like manner as when he said, Destroy this temple, John 2:19; meaning the temple of his body. And it is certain, that as he is spoken of in Scripture, as the only foundation of the Church, so this is that which the apostles and evangelists laid in their preaching. It is in respect of laying this, that the names of the twelve apostles (not of St. Peter only) were equally inscribed on the twelve foundations of the city of God, Revelation 21:14. The gates of hell — As gates and walls were the strength of cities, and as courts of judicature were held in their gates, this phrase properly signifies the power and policy of Satan and his instruments. Shall not prevail against it — Not against the Church universal, so as to destroy it. And they never did. There hath been a small remnant in all ages.