תנור תחלתו ארבעה ושיריו ארבעה דברי רבי מאיר. וחכמים אומרים במה דברים אמורים בגדול אבל בקטן תחלתו כל שהוא ושיריו רובו. משתגמר מלאכתו. איזהו גמר מלאכתו. משיסיקנו כדי לאפות בו סופגנין. רבי יהודה אומר משיסיק את החדש כדי לאפות בישן סופגנין:
A baking oven originally must be no less than four handbreadths [high] and what is left of it four handbreadths, the words of Rabbi Meir. But the sages say: this applies only to a large oven but in the case of a small one it originally can be [any height] and what is left is the greater part of it. [Its susceptibility to impurity begins] as soon as its manufacture is completed. What is regarded as the completion of its manufacture? When it is heated to a degree that suffices for the baking of spongy cakes. Rabbi Judah says: when a new oven has been heated to a degree that sufficed for the baking of spongy cakes in an old one.