וְגַ֧ם הַכֹּהֲנִ֛ים הַנִּגָּשִׁ֥ים אֶל־יְהוָ֖ה יִתְקַדָּ֑שׁוּ פֶּן־יִפְרֹ֥ץ בָּהֶ֖ם יְהוָֽה׃
And let the priests also, that come near to the LORD, sanctify themselves, lest the LORD break forth upon them.’
Read kabbalistic (mystical) interpretation of Exodus 19:22: and classical mystical sources.