וְכִֽי־יָמ֨וּת מֵ֤ת עָלָיו֙ בְּפֶ֣תַע פִּתְאֹ֔ם וְטִמֵּ֖א רֹ֣אשׁ נִזְר֑וֹ וְגִלַּ֤ח רֹאשׁוֹ֙ בְּי֣וֹם טָהֳרָת֔וֹ בַּיּ֥וֹם הַשְּׁבִיעִ֖י יְגַלְּחֶֽנּוּ׃
And if any man die very suddenly beside him, and he defile his consecrated head, then he shall shave his head in the day of his cleansing, on the seventh day shall he shave it.
Read kabbalistic (mystical) interpretation of Numbers 6:9: and classical mystical sources.