9 “They shall hear My Words, for they have prevailed.” My Words have prevailed over their words. They have spoken clever things, I true things. To praise one who talks well is one thing, to praise One who speaks truth is another. “They shall hear My Words, for they have prevailed.” How have they prevailed? Who of them has been taken offering sacrifice, when such things were forbidden by the law, and has not denied it? Who of them has been taken worshipping an idol, and has not exclaimed, “I did it not,” and feared lest he should be convicted?
Such servants has the devil. But how have the Words of the Lord prevailed? “Behold, I send you forth as sheep in the midst of wolves. Fear not those who kill the body,” etc. He gave them fear, He suggested hope, He kindled love. “Fear not death,” He says. Do ye fear death? I die first. Fear ye, lest a hair of your head perish? I first rise again in the flesh uninjured. Rightly have ye heard His Words, for they have prevailed. They spoke, and were slain; they fell, and yet stood.
And what was the result of so many deaths of martyrs, save that those words prevailed, and the earth being, so to speak, watered by the blood of Christ's witnesses, the cross of the Church shot up everywhere? How have they “prevailed”? We have said already, when they were preached by men who feared not. Feared not what? Neither banishment, nor losses, nor death, nor crucifixion: for it was not death alone that they did not fear; but even crucifixion, a death than which none was thought more accursed. It the Lord endured, that His disciples might not only not fear death, but not even that kind of death. When then these things are said by men that fear not, they have prevailed.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)