קָרְב֥וּ רִֽיבְכֶ֖ם יֹאמַ֣ר יְהוָ֑ה הַגִּ֙ישׁוּ֙ עֲצֻמ֣וֹתֵיכֶ֔ם יֹאמַ֖ר מֶ֥לֶךְ יַעֲקֹֽב׃
Produce your cause, saith the LORD; Bring forth your reasons, saith the King of Jacob.
Read halakhic rulings (Jewish law) on Isaiah 41:21: and classical halakhic sources.