What is "the apple of the eye"?

Got Questions:
Several verses in the Bible mention “the apple of the eye.” This ancient metaphor is a reference to the “pupil” of the eye, which is exactly how some Bible translations render it. Here are three Old Testament uses of the phrase the apple of the eye:

The wise father says to his son, “Keep my commands and you will live; guard my teachings as the apple of your eye” (Proverbs 7:2).

The psalmist prays, “Keep me as the apple of your eye; hide me in the shadow of your wings” (Psalm 17:8).

And in Deuteronomy 32:10 Moses relates a poetic description of God’s care for Israel: “In a desert land he found him, in a barren and howling waste. He shielded him and cared for him; he guarded him as the apple of his eye.”

At the risk of getting a little word-nerdy, let’s look at some of the Hebrew behind the phrase. The “apple” in the apple of the eye is a translation of the Hebrew word for “apple,” ishon, which is related to the word ish, meaning “man.” Etymologically, the ishon of the eye is “the little man of the eye.” Have you ever looked someone in the eye and seen your own reflection in their pupil? That’s the “little man,” right in the center of the eye.

The apple of one’s eye is a very sensitive place and therefore very protected. Think about your own eye for a moment. What happens if something flies in it or toward it? Your eyelids reflexively close, your head turns, and your hands position themselves to ward off the threat. Our eyesight is valuable, and our body naturally protects that vulnerable spot to prevent injury.

So, the instruction in Proverbs 7:2 is to hold godly wisdom in high regard as the valuable thing it is. The prayer in Psalm 17:8 is for God to keep guard over us as He would the pupil of His own eye. And the description of God’s care for His people in Deuteronomy 32:10 emphasizes Israel’s vulnerability and God’s tender, loving affection. God provided complete protection; His people were a priority. In the “howling wilderness,” God provided manna for them to eat, water from a rock, and safety from their enemies. His care was as automatic as if He were guarding the center of His eye from harm. What a loving God we serve.

God held the Israelites as the apple of His eye, rebellious and stiff-necked though they were in the wilderness. Being the apple of His eye, they were most cherished. And God’s care for His people has not diminished with time. ....