Jews and Tattoos

The LORD said to him, “I promise, if anyone kills Cain, sevenfold vengeance shall be taken on him.” And the LORD put a mark on Cain, lest anyone who met him should kill him.

You shall not round off the side-growth (pe'at) on your head, or destroy the side-growth (pe'at) of your beard.

You shall not make (titnu) gashes in your flesh for the dead, or incise (titnu) any marks on yourselves: I am the LORD.

(2) for the soul here denotes a dead body (as it is correctly rendered in the Aramaic translation). The nun is not doubled with a dagesh for the sake of ease of pronunciation. (3) tattoo marks Some say that this commandment is connected to the previously-mentioned incision because there are people who tattoo themselves as a sign of mourning, using fire to brand their body with specific shapes. Nowadays, also, people mark their faces when they are young in order to distinguish themselves. The word tattoo is doubled, like “and that which comes out of it” [Isaiah 42:5]. It comes from “and have them impale” [Numbers 25:4]. The opinion of the Aramaic translator, however, seems to be that the word has no cognate, and this too is plausible.

4 And they shall sprout like grass, Like willows by watercourses. 5 One shall say, “I am the LORD’s,” Another shall use the name of “Jacob,” Another shall mark his arm “of the LORD” And adopt the name of “Israel.” 6 Thus said the LORD, the King of Israel, Their Redeemer...

One who writes a tattoo in the skin of their fellow - both are obligated by the Torah. What is the specific case being discussed? When two people act intentionally, but if they did so accidentally, they are exempt (from penalty). If one does so accidentally, and one does so intentionally, the former is exempt while the later is obligated.

And one is only obligated when the tattoo is done with ink or blue for the purposes of idol worship.

If one peels their skin with a blade, they are exempt.

If one inscribes on their slave in order that they not run away, [the owner] is exempt.

One who cuts into their skin the names of the dead with their hand is exempt, and one who does so with a tool is obligated.

One who cuts into their skin for purposes of idol worship is obligated, whether done with their hand or with a tool.

MISHNA: One who imprints a tattoo, by inserting a dye into recesses carved in the skin, is also liable to receive lashes. If one imprinted on the skin with a dye but did not carve the skin, or if one carved the skin but did not imprint the tattoo by adding a dye, he is not liable; he is not liable until he imprints and carves the skin, with ink, or with kohl [keḥol], or with any substance that marks. Rabbi Shimon ben Yehuda says in the name of Rabbi Shimon: He is liable only if he writes the name there, as it is stated: “And a tattoo inscription you shall not place upon you, I am the Lord” (Leviticus 19:28).
GEMARA: Rav Aḥa, son of Rava, said to Rav Ashi: Is Rabbi Shimon saying that one is liable only if he actually inscribes the words “I am the Lord” in his skin? Rav Ashi said to him: No, he is saying as bar Kappara teaches: One is liable only if he inscribes a name of an object of idol worship, as it is stated: “And a tattoo inscription you shall not place upon you, I am the Lord,” which means: Do not place an idolatrous name on your skin, as I am the Lord, and no one else.