Mishnayos Keilim Perek 8 Mishnah 9

בור שיש בו בית שפיתה (a smelting pot which has a bottom or foot on which it can rest – a hole in the ground with an arrangement for putting a pot over fire) – a person who digs in the ground and plasters over the spot over with clay/mud and the plaster can stand (or form a vessel) on its own, such as the oven the son of Dinai, as is taught in the Mishnah above in the chapter “A Baking Oven, its Beginning/"תנור תחלתו" (see Tractate Kelim, Chapter 5, Mishnah 10 at the conclusion- who, according to Bartenura, states that he was a robber and would bake his bread in an oven like this and make these kinds of ovens, or a place where trials took place frequently; see also Tractate Sotah, Chapter 9, Mishnah 9, where this name also appears). But there are those who have the reading of כור/smelting pot with the letter כ'/Kaf (and not the ב'./Bet – as found in our editions of the Mishnah) – and it is a utensil/vessel in which they smelt in it gold and the silver and metals, he language of an iron furnace/כור ברזל. But to me, it appears that it is an oven of a blacksmith.

פורנה (a stationary large baking oven) – a large earthenware oven and its opening is at its side like our eye. But it is pure, because it is used with the ground, as is taught in the Tosefta (Tractate Kelim Bava Kamma, Chapter 6, Halakha 17).

לזבז – a thick rim.

אסטגיות (rims, moldings around a stove) – perforations similar to those that they make for ovens.

שפיות – a thin rim. But the Halakha is according to the first Tanna/teacher. But my Rabbis explained that a לזבז/thick rim and אסאגיות/rims, moldings around a stove and שפיות/thin rims are all one [thing]. But they do not disagree other than that each one was different according to the language that he heard from his master, and a person is obligated to state [something] according to the language of his teacher (see also Tractate Eduyot, Chapter 1, Mishnah 3).