MISHNA: One who writes two letters on Shabbat during one lapse of awareness is liable. The following substances used as ink are explained in the Gemara. One is liable if he wrote with deyo, with sam, with sikra, with gum [komos], or with copper sulfate [kankantom] or with any substance that makes a mark. If one wrote on two walls of a house that form a corner, or on two parts of a writing tablet, and the two items are read together, he is liable. One who writes on his flesh on Shabbat is liable. If one unwittingly scratches letters on his flesh on Shabbat, Rabbi Eliezer deems him liable to bring a sin-offering and the Sages deem him exempt.

If one wrote with liquids or with fruit juice, or if one drew letters with road dust, with scribes’ dust that they use to dry the ink, or with any substance with which the writing does not endure, he is exempt. Similarly, if one wrote by holding the pen on the back of his hand, with his foot, with his mouth, or with his elbow; if one wrote only a single letter, even if it was adjacent to other preexisting writing; or if one wrote over other writing; if one meant to write the letter ḥet and instead wrote the two halves of the ḥet as two instances of the letter zayin; if one wrote one letter on the ground and one on a rafter; if one wrote one letter on two walls of a house, or on two parts of a writing tablet that are not read together, he is exempt. If one wrote one letter as an abbreviation representing an entire word, Rabbi Yehoshua ben Beteira deems him liable to bring a sin-offering, and the Rabbis deem him exempt.

GEMARA: The Gemara defines the terms used in the mishna. Deyo is deyota made from soot. Sam is samma, which is yellow-tinged arsenic. Sikra, Rabba bar bar Ḥana said: It is called sikreta in Aramaic and is a lead-based red paint. Komos is koma in Aramaic, and it is an ink made with gum Arabic from the sap of a tree. Kankantom, Rabba bar bar Ḥana said that Shmuel said: This is the black substance used by cobblers, copper sulfate.

And we learned in the mishna that one who writes with any substance that makes a mark is liable. The Gemara asks: What does this statement come to include? The Gemara answers: It comes to include that which Rabbi Ḥananya taught with regard to writing a bill of divorce: If one wrote it with the juice of the fruit called teriya, or with gallnut juice instead of ink, it is valid. Similarly, Rabbi Ḥiyya taught: If one wrote a bill of divorce with lead, with soot (ge’onim), or with shoeblack, it is valid. Since those substances leave a permanent mark, one who writes with them on Shabbat is liable.

We learned in the mishna: If one unwittingly scratches letters on his flesh on Shabbat, Rabbi Eliezer deems him liable to bring a sin-offering and the Sages deem him exempt. It was taught in a baraita that Rabbi Eliezer said to the Rabbis: Didn’t the infamous ben Stada take magic spells out of Egypt in a scratch on his flesh? They said to him: He was a fool, and you cannot cite proof from a fool. That is not the way that most people write. Incidentally, the Gemara asks: Why did they call him ben Stada, when he was the son of Pandeira? Rav Ḥisda said: His mother’s husband, who acted as his father, was named Stada, but the one who had relations with his mother and fathered him was named Pandeira. The Gemara asks: Wasn’t his mother’s husband Pappos ben Yehuda? Rather, his mother was named Stada and he was named ben Stada after her. The Gemara asks: But wasn’t his mother Miriam, who braided women’s hair? The Gemara explains: That is not a contradiction. Rather, Stada was merely a nickname, as they say in Pumbedita: This one strayed [setat da] from her husband.

We learned in the mishna: If one wrote only a single letter, even if it was adjacent to other preexisting writing, he is exempt. The Gemara asks: Who is the tanna whose opinion is cited in the mishna? Rava bar Rav Huna said: This halakha is not in accordance with the opinion of Rabbi Eliezer, as if it were in accordance with the opinion of Rabbi Eliezer, didn’t he say: One who adds a single thread to a previously woven fabric is liable for weaving? In his opinion, although a single thread or letter is insignificant in and of itself, one is liable because adding even a small measure to existing material is significant.

We learned in the mishna: If one wrote over other writing he is exempt. The Gemara asks: Who is the tanna whose opinion is cited in the mishna? Rav Ḥisda said: This halakha is not in accordance with the opinion of Rabbi Yehuda, as it was taught in a baraita: If one needed to write the Tetragrammaton, the name of God, in a Torah scroll, and became confused and intended instead to write the name Yehuda, and while intending to write Yehuda he erred and omitted the letter dalet, thereby writing the name of God, he should do the following. He passes a quill with more ink over the name and sanctifies it, i.e., he writes it with the intention required when writing a holy name. This is the statement of Rabbi Yehuda. And the Rabbis say: Even if he adds ink over what he wrote, this writing of God’s name is not ideal. Apparently, according to Rabbi Yehuda, writing over other writing is considered writing anew.

A tanna taught in a baraita: If one wrote a single letter and thereby completed a book, or if one wove a single thread and thereby completed an entire garment, he is liable. The Gemara asks: Who is the tanna whose opinion is cited in the baraita? Rava bar Rav Huna said: It is the opinion of Rabbi Eliezer, who said: One who adds a single thread to a previously woven fabric is liable for weaving. Rav Ashi said: Even if you say that in accordance with the opinion of the Rabbis, one who does so to complete a garment is different. Even if he is not liable for weaving, he is liable at least for striking a blow with a hammer to complete the production process of a vessel.

Rabbi Ami said: If one wrote one letter on paper in Tiberias and one letter on paper in Tzippori, he is liable because he performed a full-fledged act of writing that is lacking only in proximity. When the two pieces of paper are brought together he will have written two associated letters. The Gemara asks: Didn’t we learn in the mishna: If one wrote one letter on two walls of a house, or on two parts of a writing tablet that are not read together, he is exempt? All the more so that this is the halakha with regard to one who wrote in two different cities. The Gemara answers: There, in the case of the parts of a tablet, there is the lack of an additional act of cutting or tearing to facilitate bringing the letters together. However, here, in the case of two cities, even though they are distant from one another, there is no lack of an additional act to facilitate bringing them together.

A tanna taught in the Tosefta: If one emended a single letter on Shabbat, he is liable. The Gemara wonders: Now, if one wrote a single letter on Shabbat he is exempt; is it possible that if one emends a single letter he is liable? Rav Sheshet said: With what are we dealing here? We are dealing with a case where one removed the roof of a ḥet and transformed it into two instances of the letter zayin, effectively writing two letters with a single correction. Rava said: It is not necessarily referring to that specific case. It could even be referring to a case where one removed the protrusion from the back of a dalet and transformed it into a reish, thereby emending the written text. One who did so is liable for performing the prohibited labor of striking a blow with a hammer to complete the production process of a vessel.

A tanna taught: If one intended to write one letter on Shabbat