וַיָּקֻ֧מוּ הַלְוִיִּ֛ם מִן־בְּנֵ֥י הַקְּהָתִ֖ים וּמִן־בְּנֵ֣י הַקָּרְחִ֑ים לְהַלֵּ֗ל לַיהוָה֙ אֱלֹהֵ֣י יִשְׂרָאֵ֔ל בְּק֥וֹל גָּד֖וֹל לְמָֽעְלָה׃
And the Levites, of the children of the Kohathites and of the children of the Korahites, stood up to praise the LORD, the God of Israel, with an exceeding loud voice.
Read halakhic rulings (Jewish law) on II Chronicles 20:19: and classical halakhic sources.