翻譯名義集 7.38

7.38

【浮囊】《五分》云：「自今聽諸比丘畜浮囊，若羊皮，若牛皮。」傳聞西域渡海之人，多作鳥翎毛袋，或齎巨牛脬，海船或失，吹氣浮身。

[Floating float-bag] The Mahīśāsaka Vinaya states: "From now on, I permit the bhikṣus to keep floating bags, whether of sheepskin or oxhide." Tradition reports that in the Western Regions, those who cross the sea often make bags of bird feathers, or carry large ox bladders; if an ocean ship is lost, they blow air into them to float their bodies.