"In the first chapter of Sukkah (page 4b and there), regarding Rabbi Yehuda, who permits [a sukkah height] up to forty or fifty cubits, it does not ask 'now fifty, etc.' Similarly, in the beginning of 'Although' (Ketubot page 57a and there), regarding 'But the sages say, a person can stay with his wife even two or three years without a marriage contract,' it appears to Rabbi Yitzchak that whenever it is clear that they mean 'even much more,' they do not question it. But here, there is no reason to interpret 'four or five' as 'even much more,' because if so, [it would imply leniency regarding] a sandal with nails. And similarly, in the chapter of the 'Daughters of Cutheans' (Niddah page 37b and there), it asks regarding 'and how long is her labor?' Rabbi Meir says 'even forty or fifty days,' because there is no reason to say 'even much more,' as it is unreasonable to consider labor blood from the beginning of pregnancy. And it appears in all these cases that the latter measure is exact, which is why they question, 'let it say the latter measure' rather than the first. And later, in 'Removing Four or Five Baskets' (Shabbat 126b), it also questions, 'now five are allowed, so four...' showing that no more is permitted due to the burden of Shabbat. Rav Chisda explains, 'four from a small storage room, five from a large one,' and Shmuel explains, 'four or five, even many,' as people say that many may be removed as long as the storage floor is not completely cleared to avoid leveling pits, as explained there. And if you ask: in the chapter 'Although' (Ketubot 60a and there), we say, 'a child may nurse even four or five years,' and it does not question this, even though it seems exact. Since there, it questions 'with his bundle on his shoulder' and answers that both are one measure, one can say this is for a lean child and this for a strong child. And as we say in the chapter 'The Forearm' (Chullin 132b), a Kohen butcher is exempt from gifts for two or three weeks, but after that, he is obligated. Rabbi Yitzchak explains that it mentions two for Rabbi, who holds in 'The One Who Has Relations with His Brother’s Wife' (Yevamot 64a) that a presumption is established after two occurrences, and three for Rabbi Shimon ben Gamliel."