Talmud zu Bereschit 17:19
וַיֹּ֣אמֶר אֱלֹהִ֗ים אֲבָל֙ שָׂרָ֣ה אִשְׁתְּךָ֗ יֹלֶ֤דֶת לְךָ֙ בֵּ֔ן וְקָרָ֥אתָ אֶת־שְׁמ֖וֹ יִצְחָ֑ק וַהֲקִמֹתִ֨י אֶת־בְּרִיתִ֥י אִתּ֛וֹ לִבְרִ֥ית עוֹלָ֖ם לְזַרְע֥וֹ אַחֲרָֽיו׃
Da sprach Gott: Nicht doch! Deine Frau Sara gebiert dir einen Sohn; den sollst du Isaak (Jizchak) nennen, und ich will meinen Bund mit ihm errichten, als ewigen Bund für seine Nachkommen nach ihm.
Jerusalem Talmud Berakhot
Why were the names of Abraham and Jacob changed but Isaac’s name was not changed? The former were given their names by their fathers; but Isaac was called Isaac by the Holy One, Praise to His Name, as it is said (Gen. 17:19) “You shall call his name Isaac”. Four were given names before they were born, and they are Isaac, Ismael, Josiah, and Solomon. Isaac, (Gen. 17:19) “You shall call his name Isaac”. Ismael as it is written (Gen. 16:11): “You shall call his name Ismael”. Josiah, (1Kings 13:2): “Behold, a son will be born to the dynasty of David; his name will be Josiah”. Solomon, (1Chr. 22:9) “Solomon will be his name”310While in 2Sam. 12:24–25 it seems that David gave the name Solomon to his son and Nathan called him Yedidiah after his birth; it is clear from Chronicles that the name Solomon was not David’s invention but prophetically pre-ordained.. All this for the just. But the wicked (Ps. 58:4) “The wicked are perverted from the womb.”
Ask RabbiBookmarkShareCopy