In Collection of Rhymes (Jiyun) and Classified Dictionary (Leipian), the pronunciation is given as fen. It is identical to the character fen. For a detailed explanation, see the annotations for the character fen. Additionally, in Collection of Rhymes (Jiyun) the pronunciation is given as pu men, and in Classified Dictionary (Leipian) the pronunciation is given as fu men, which are identical to the pronunciation of the character ben. Collection of Rhymes (Jiyun) explains it as a blazing flame. Sometimes it is also written in a variant form (fen).