וַיֹּ֨אמֶר אֶלְעָזָ֤ר הַכֹּהֵן֙ אֶל־אַנְשֵׁ֣י הַצָּבָ֔א הַבָּאִ֖ים לַמִּלְחָמָ֑ה זֹ֚את חֻקַּ֣ת הַתּוֹרָ֔ה אֲשֶׁר־צִוָּ֥ה יְהוָ֖ה אֶת־מֹשֶֽׁה׃
And Eleazar the priest said unto the men of war that went to the battle: ‘This is the statute of the law which the LORD hath commanded Moses:
Read kabbalistic (mystical) interpretation of Numbers 31:21: and classical mystical sources.