וַיֹּ֤אמֶר אֱלֹהִים֙ אֶל־אַבְרָהָ֔ם שָׂרַ֣י אִשְׁתְּךָ֔ לֹא־תִקְרָ֥א אֶת־שְׁמָ֖הּ שָׂרָ֑י כִּ֥י שָׂרָ֖ה שְׁמָֽהּ׃
And God said unto Abraham: ‘As for Sarai thy wife, thou shalt not call her name Sarai, but Sarah shall her name be.
Read halakhic rulings (Jewish law) on Genesis 17:15: and classical halakhic sources.