Sylvia avoided Penny's penetrating gaze. "Danger at the Drawbridge" by Mildred A. Wirt

Those large, penetrating grey eyes; each seemed to be looking into his own as in a mirror. "The Grey Cloak" by Harold MacGrath

There we shall all have to stand, and let that all- penetrating light search us through and through. "The Expositor's Bible: Colossians and Philemon" by Alexander Maclaren