Broad Glossary (Guangyun), Collection of Rhymes (Jiyun), Rhyme Meetings (Yunhui), and Correct Rhymes (Zhengyun) state the pronunciation is fen. It refers to a strange sheep found within the earth. The Discourses of Lu (Luyu) records that the monster in the earth is called fen. The commentary explains: the fen sheep refers to a lamb whose male or female characteristics have not yet developed. It is also written as fen. Furthermore, the Collection of Rhymes (Jiyun) and Rhyme Meetings (Yunhui) state the pronunciation is fen. The meaning is the same.