וְשֶׂ֣רֶט לָנֶ֗פֶשׁ לֹ֤א תִתְּנוּ֙ בִּבְשַׂרְכֶ֔ם וּכְתֹ֣בֶת קַֽעֲקַ֔ע לֹ֥א תִתְּנ֖וּ בָּכֶ֑ם אֲנִ֖י יְהוָֽה׃
Ye shall not make any cuttings in your flesh for the dead, nor imprint any marks upon you: I am the LORD.
Read kabbalistic (mystical) interpretation of Leviticus 19:28: and classical mystical sources.