ויהיו חיי שרה מאה שנה ועשרים שנה ושבע שנים. לְכָךְ נִכְתַּב שָׁנָה בְּכָל כְּלָל וּכְלָל, לוֹמַר לְךָ שֶׁכָּל אֶחָד נִדְרָשׁ לְעַצְמוֹ, בַּת ק' כְּבַת כ' לְחֵטְא, מַה בַּת כ' לֹא חָטְאָה, שֶׁהֲרֵי אֵינָהּ בַּת עֳנָשִׁין, אַף בַּת ק' בְּלֹא חֵטְא, וּבַת כ' כְּבַת ז' לְיֹפִי: ויהיו חיי שרה מאה שנה ועשרים שנה ושבע שנים AND THE LIFE OF SARAH WAS 127 YEARS (literally, 100 years, 20 years and 7 years) — The reason the word שנה is written at every term is to tell you that each term must be explained by itself as a complete number: at the age of one hundred she was as a woman of twenty as regards sin — for just as at the age of twenty one may regard her as having never sinned, since she had not then reached the age when she was subject to punishment, so, too, when she was one hundred years old she was sinless — and when she was twenty she was as beautiful as when she was seven (Genesis Rabbah 58:1).
שני חיי שרה. כֻּלָּן שָׁוִין לְטוֹבָה: שני חיי שרה THE YEARS OF SARAH’S LIFE — The word years is repeated and without a number to indicate that they were all equally good.