Tosefta do Kapłańska 16:12

The "ladleful of corpse-mold" that they spoke of (see Mishnah Oholot 2:2): [It defiles if] it is [the equivalent of the area] from the joints^*מקשרי (GR"A) of his fingers and upwards, the words of Rabbi Meir. And the Sages say, a fistful (Lev. 16:12). A "clod of earth from an area of a doubtful grave" and "a clod of earth from the land of the Gentiles" (Toh. 5:1): Their measure is the size of a large stopper [used] by sack makers, which is the equivalent [size of] the seal of packing bags. And this [size] is [also found] on the upper side of the seal of a Bethlehem jug. Rabbi Tarfon says, the dust of a doubtful grave area [imparts corpse-impurity] if it is of sufficient size to cover up a bone the size of a barleycorn. The "fist" that they spoke of (Mishnah Oholot 13:1): Rabbi Tarfon straightens out the tips of his fingers and shows [the measurement to his students]. Rabbi Akiva closes up the tips of his fingers and shows it. Rabbi Yehuda rests his fingers on top of the biggest one (i.e., the thumb), folded, [and] he goes back and measures^*מודד not מוריד ("brings it down") (GR"A). Rabbi Yosei says, it is the size of the head of a big sheep from Tzippori. Others said in his name, "a handbreadth and a third of a handbreadth." And so they went on measuring before Ben Batiach came along (Kel. 17:12). § The measures of wine and and oil: Their minimum size is like a large stopper for them (i.e., their containers). And what is "a large stopper for them"? One that enters through their mouths (i.e., of the containers). When do these words apply? From below, but from the side, behold, they are impure because they receive from the drainage point downward. § [Regarding leather vessels,] in their initial state, they are not susceptible to impurity until one has blown it up and scraped it (i.e., polished the leather surface). [If] they were scraped, their minimum size [for impurity] is the same as their [actual] size. Rabbi Shimon says, the measure of their minimum size is that of liquids.