The Jesuit turned away, saying, sarcastically, "The Protestants are impenetrable rocks." "You are mistaken," said Kutnaur, "it is Christ that is the Rock, and we are firmly fixed upon Him.
— John Foxe
The future is hidden by a dark impenetrable veil, and yet we struggle to pierce through it.
— Joseph Barber Lightfoot
You look at a star for two reasons, because it is luminous, and because it is impenetrable. You have beside you a sweeter radiance and a greater mystery, woman.