The 41st prohibition is that we are forbidden from tattooing our bodies with blue, red or other markings, as is done by idol worshippers and common among the Copts to this day.

The source of this prohibition is G‑d's statement (exalted be He),1 "Do not make any tattoo marks."

One who transgresses this prohibition is punished by lashes.2

The details of this mitzvah have been explained in the end of tractate Makkos.