[We] write [it] with anything: with ink, with orpiment, with red pigment, with gum, with ferrous sulfate, or with anything which is lasting. [We] do not write [it] with liquids, nor with fruit juice, nor with anything which is not lasting.  [We] write [it] upon anything: on the leaf of an olive tree; or on the horn of a cow, and he gives her the cow; or on the hand of a slave, and he gives her the slave. R' Yose the Galilean says: [We] do not write [it] on a living creature, nor on food.