וְכִבֶּ֨ס בְּגָדָ֜יו הַכֹּהֵ֗ן וְרָחַ֤ץ בְּשָׂרוֹ֙ בַּמַּ֔יִם וְאַחַ֖ר יָב֣וֹא אֶל־הַֽמַּחֲנֶ֑ה וְטָמֵ֥א הַכֹּהֵ֖ן עַד־הָעָֽרֶב׃
Then the priest shall wash his clothes, and he shall bathe his flesh in water, and afterward he may come into the camp, and the priest shall be unclean until the even.
Read kabbalistic (mystical) interpretation of Numbers 19:7: and classical mystical sources.