Mishnah Shabbat 12

¹One who builds: how much must he build to be liable? He who builds any amount, and he who chisels, and he who strikes with a hammer or with an axe, and he who bores [a hole] of any size, is liable. This is the general principle: whoever does work and his work endures on Shabbat, he is liable. Rabban Shimon ben Gamaliel says: even one who strikes with a hammer on the anvil at the completion of his work is liable, because he is as one who improves his work. ²He who plows any amount, or who weeds, or who prunes [trees], or who cuts off young shoots, no matter the amount, is liable. He who gathers wood: if in order to effect an improvement, [he is liable] for any amount; if for lighting a fire, as much as is required for boiling a light egg. He who collects grasses: if to effect an improvement, [he is liable] for any amount; if for an animal, as much as fits in a kid’s mouth. ³He who writes two letters, whether with his right hand or with his left hand, whether the same letter or two different letters or in two pigments, in any language, is liable. Rabbi Jose said: they made one liable for writing two letters only because [he makes] a mark, since this is how they would write on each board of the tabernacle, to know which its companion was. Rabbi Judah said: we find a short name [forming part] of a long name: “Shem” as part of “Shimon” or “Shmuel”, “Noah” as part of “Nahor”, “Dan” as part of “Daniel”, “Gad” as part of “Gaddiel”. ⁴He who writes two letters in one state of unawareness is liable. He who writes with ink, arsenic, red chalk, gum, sulphate of copper or with anything that leaves a mark, on the angle of two walls, or on the two leaves of a ledger, and they [the two letters] are read together, is liable. He who writes on his flesh, he is liable. He who scratches a mark on his flesh: Rabbi Eliezer declares him liable to a sin-offering; But the sages exempt him. ⁵If he wrote with liquids, or with fruit juice, on the dust of the road, or on writer’s powder, or with anything that cannot endure, he is exempt. [If he wrote] with the back of his hand, with his foot, with his mouth, or with his elbow; If he wrote one letter near [other] writing, If he wrote on top of other writing; If he intended to write a cheth but wrote two zayyinin; [If he wrote] one [letter] on the ground and another on a beam; If he wrote on two walls of the house, or on two leaves of a ledger which are not read together, he is exempt. If he wrote one letter as an abbreviation: Rabbi Joshua ben Bathyra declares him liable, But the sages exempt him. ⁶He who writes two letters in two states of unawareness, one in the morning and one in the evening: Rabban Gamaliel declares him liable; But the sages exempt him.