Sarah shall her name be — The same letter is added to her name that was to Abraham's. Sarai signifies my princess, as if her honour were confined to one family only: Sarah signifies a princess, viz. of multitudes.
Related Commentaries of Genesis 17:15
Genesis 17:15
15 And God said unto Abraham, As for Sarai thy wife, thou shalt not call her name Sarai, but Sarahe shall her name be.