分別功德論 4.32

4.32

所以稱婆差比丘者，本在家時常以家為患，出家求道常在露坐。若入房室常苦氣閉，如似掩口，是以常求露坐思惟行道，然後身體調和氣息通暢行道無閡。以是因緣，稱婆差露坐第一。

The reason why Bhikṣu Vatsa was praised is that formerly, while living at home, he always considered home life an affliction. Upon leaving home to seek the Path, he always sat in the open air. If he entered a room, he was constantly afflicted by suffocating air, as if his mouth were being covered. Therefore, he always sought to sit in the open air to contemplate and practice the Path, after which his body became harmonized, his breath circulated smoothly, and his practice of the Path proceeded without obstruction. Due to these causes and conditions, Vatsa was praised as foremost in sitting in the open air.