וְהַשֹּׂרֵ֣ף אֹתָ֔ם יְכַבֵּ֣ס בְּגָדָ֔יו וְרָחַ֥ץ אֶת־בְּשָׂר֖וֹ בַּמָּ֑יִם וְאַחֲרֵי־כֵ֖ן יָב֥וֹא אֶל־הַֽמַּחֲנֶֽה׃
And he that burneth them shall wash his clothes, and bathe his flesh in water, and afterward he may come into the camp.
Read kabbalistic (mystical) interpretation of Leviticus 16:28: and classical mystical sources.