四分比丘戒本疏 1.41

1.41

問：前房既已二殘合制，何不通收此殘為三？答：文詞便易，義又相因，是故前房二殘合制過量無量。義既相違，作法文詞復不便易，故別制也。

Question: Since in the previous hut [precept] two saṃghāvaśeṣas were combined into one rule, why not also include this saṃghāvaśeṣa to make three? Answer: The phrasing was convenient and the meanings were mutually dependent, which is why in the previous hut [precept] the two saṃghāvaśeṣas were combined into one rule. [Here,] exceeding measurements and having no measurements are mutually contradictory in meaning, and the phrasing of the legal procedure is not convenient; therefore, a separate rule was instituted.