זֶ֤ה יֹאמַר֙ לַֽיהוָ֣ה אָ֔נִי וְזֶ֖ה יִקְרָ֣א בְשֵֽׁם־יַעֲקֹ֑ב וְזֶ֗ה יִכְתֹּ֤ב יָדוֹ֙ לַֽיהוָ֔ה וּבְשֵׁ֥ם יִשְׂרָאֵ֖ל יְכַנֶּֽה׃ (פ)
One shall say: ‘I am the LORD’S’; And another shall call himself by the name of Jacob; And another shall subscribe with his hand unto the LORD, And surname himself by the name of Israel.
Read halakhic rulings (Jewish law) on Isaiah 44:5: and classical halakhic sources.