If the Torah forbids tattoos, why doesn't it ban peircings. Isn't it self harm? If you could quote your sources that would be appreciated.
For an explanation why piercings would not be considered self harm/mutilation click here
Getting a tattoo is a torah violation of the following pasuk in ויקרא פרק י"ט פסוק כ"ח :
וְשֶׂ֣רֶט לָנֶ֗פֶשׁ לֹ֤א תִתְּנוּ֙ בִּבְשַׂרְכֶ֔ם וּכְתֹ֣בֶת קַֽעֲקַ֔ע לֹ֥א תִתְּנ֖וּ בָּכֶ֑ם אֲנִ֖י יְהֹוָֽה׃
You shall not make gashes in your flesh for the dead, or incise any marks on yourselves: I am יהוה.
Even though the pasuk mentioned the prohibition of tattooing alongside gashing oneself, each one is a separate prohibition. As stated in Ramabam הל’ ע"ז פרק י"ב הל’ י"א ,Shach 180/6 and Chinuch Mitzvah 253, the prohibition of tattooing is because worshippers of idols would tattoo images of their gods onto their skin. Hence, there is no connection between the prohibition of tattooing and self harm.