Chou Collection, Upper Volume
Radical: Mouth (kǒu)
Character: bi
Kangxi strokes: 17
Page 212, Entry 02
According to the Extensive Rhymes (Guangyun) and Collected Rhymes (Jiyun), the pronunciation is bi (falling tone).
According to the Jade Chapters (Yupian), it describes the sound of panting.
Also, according to the Collected Rhymes (Jiyun), the pronunciation is xi (falling tone). It is equivalent to the character xi. See the notes on the character xi above for details.
Also, in the Hunting Rhapsody (Jiaolie Fu) by Yang Xiong, it is written: "Feilian and the Master of Clouds, inhaling and exhaling with force."
The commentary by Shigu states: Inhaling and exhaling describes the act of opening wide. Force refers to gathering together. The character bi is pronounced as ji (falling tone).