Parshat Chayei Sarah opens with the Pasuk, “Sarah’s lifetime was one hundred years, twenty years, and seven years; the years of Sarah’s life.”
Why does the Pasuk have to repeat the word years? Rashi says that the word is repeated because Sarah’s life was divided into three separate periods. At age one hundred, she was as sinless as she was at twenty, as a person does not suffer heavenly punishment at the age of twenty. At the age of twenty, she still had the wholesome beauty as a seven year old, whose beauty is natural.
R’ Moshe Feinstein commented here that, despite Sarah’s breathtaking beauty, everyone that saw her recognized her purity and innocence.