apple of one's eye
Special favorite, beloved person or thing, as in The youngest was the apple of his father's eye. This term, which rests on the ancients' idea that the eye's pupil is apple-shaped and that eyes are particularly precious, appears in the Bible (Deuteronomy 32:10). [Early 1600s]
apple of (one's) eye
One that is treasured: Her grandson is the apple of her eye.
apple of one's eye, the
A cherished person or thing. The term comes from the ancient concept that the eye’s pupil was a solid, apple-shaped body, and, being essential to sight, was precious. It appears in the Bible (Deuteronomy 32:10): “He [the Lord] kept him [Israel] as the apple of his eye.”
apple of my eye
A most favorite or cherished person. In Psalm 17:8, the Psalmist asks God to “keep me as the apple of your eye.”