Référence sur Les Nombres 15:42

Shammai says: “[Dough] of a kav or more is subject to the law of hallah.” And Hillel says: “Of two kavs or more.” But the Sages say: “Neither according to the opinion of this one nor according to the opinion of this one, but [dough of] a kav and a half is subject to the law of hallah.” And after they increased the measures they said: “[Dough of] five quarters is subject. Rabbi Yose said: “Five are exempt, five and more are liable.”