The Hebrew words that we translate “apple of the eye” refer to the center of the eye, the pupil. But the expression also refers to someone who is light valued by another (as in “his son is the apple of his eye”). The phrase occurs several times in the Bible. Deuteronomy 32:10 says that God guarded Israel “as the apple of His eye.” The prayer of Psalm 17:8 implores God, “Keep me as the apple of Your eye; hide me under the shadow of Your wings.”