俱舍論記 11.84

11.84

「外西南角至不如法事」者，釋善法堂。《正理論》云「城外西南角有大善法堂。三十三天時集詳辨，制伏阿素洛等如法不如法事，名善法堂。」

"Outside the southwest corner... matters contrary to the Dharma": this explains the Sudharmā Hall. The *Nyāyānusāra* says: "Outside the southwest corner of the city is the great Sudharmā Hall. The Trāyastriṃśa devas assemble there at times to deliberate in detail on subduing the asuras and on matters in accordance with the Dharma or contrary to the Dharma; hence it is named the Sudharmā Hall."