四分律行事鈔資持記 3.240

3.240

諸部中，初科。二種帶者，彼律：因乞食比丘旋風吹去內衣，佛言，應著腰帶；諸比丘散縷作，紐縷作，空中作，佛言：散縷紐縷，盡不聽；空中者，應當中縫（一也），若織編作（二也）。

Under the other schools, in the first heading: regarding the "two kinds of waistbands", in that Vinaya: because an alms-begging bhikṣu had his inner robe blown off by a whirlwind, the Buddha said they should wear waistbands; the bhikṣus made them with loose threads, twisted threads, or in the air, and the Buddha said: "Loose threads and twisted threads are entirely disallowed; those made in the air should be sewn down the middle (this is the first), or braided and woven (this is the second)."