וְנִקֵּ֖יתִי דָּמָ֣ם לֹֽא־נִקֵּ֑יתִי וַֽיהוָ֖ה שֹׁכֵ֥ן בְּצִיּֽוֹן׃
And I will hold as innocent their blood that I have not held as innocent; And the LORD dwelleth in Zion.
Read halakhic rulings (Jewish law) on Joel 4:21: and classical halakhic sources.