This title (hereafter, the Hand Mirror) reveals in part the purpose of the authorʼs writing the work, as he seems to have had the intention of ensuring this text would be a convenient device like a hand mirror for the readers to reflect and grasp intricate meanings of various Seon texts rather than delving into the import of the Seon per se. The Hand Mirror is said to have been written in the tradition of Guifeng 四種禪 Zongmiʼs 宗密 (780–841) Chanyuan zhujuanji duxu 禪源諸詮集都序 which was composed in an attempt to create a doctrinal taxonomy of more than a hundred of Seon texts that proliferated in the Tang dynasty 唐代. Thus Geungseon classified and annotated the tenets of Seon by analyzing the instructions, praises, critique, and commentaries on gongan 公案 in the writings of eminent Seon monks after the thirteenth century. Baekpa makes an effort to valorize the tradition of the Imje school 臨濟宗, which places the top priority on Patriarchal Seon 祖禪. What is distinctive about the Hand Mirror is the degree of its reliance on Korean Seon literature, rather than Chinese Chan sources. Some of the major Korean sources include:

1. Seonmun yeomsong chip 禪門拈頌集 composed in 1226 by Jin-gak Hyesim 慧諶 (1178–1234), the most prominent student of Bojo Jinul 知訥 (1158–1210), the de facto founder of Korean Seon Buddhism. This massive collection of edifying ancient precedents from Seon and pre-Seon Buddhist literature is comprised by prose comments 拈 and verse comments 頌 on the 1,463 cases selected from the Seon texts.
2. Seonmun yeomsong seolhwa 禪門拈頌說話 (1685) by Gugok Gag-un 龜谷覺雲 (d.u.), a disciple of Hyesim.
3. Seonmun yeomsongjip sagi 禪門拈頌集私記 and Seonmun ojong kangyo sagi 禪門五宗綱要私記 by Baekpa.
4. Seonmun ojong gangyo 禪門五宗綱要 (Essentials of the Five Chan Schools) by Hwanseong Jian 喚惺志安 (1644–1729), an eminent Buddhist of the latter Joseon dynasty. This one-volume collection of excerpts (HBJ 9.459a–467b) from such works as the Rentian yanmu 人天眼目 (Eye of Humans and Gods, 1188) and the Seonmun gangyo jip 禪門綱要集 outlines the five Chan schools. According to the bookʼs brief descriptions on each school, the Linji school clarifies Seon masters' unsurpassed capacities and functions; the Yunmen school 雲門宗 is concerned with severing mundane views; the Caodong school 曹洞宗 explicates how to reach the ultimate state; the Weiyang school 潙仰宗 illuminates two domains of our mind, i.e. essence and function 體用; and the Fayan school 法眼宗 elucidates the truth of mind only 唯心. In this manner, the book succinctly draws out doctrinal essentials of these Chan schools from their texts. For more information, see Kim, Hogwi 김호귀 2006, “Seonmun ojong kangyo ŭi kuSeong gwa sasangjŏk t'ŭkching 『禪門五宗綱要』 (의구성과사상적특징 )” Han-guk seonhak 韓國禪學 Vol. 15.
5. Seonmun gangyo jip (Essentials of the Chan Schools, 1531) attributed to Jinjeong Cheonchaek 眞靜天頙 (b. 1206–1209), a monk of the late Goryeo dynasty. The Seon theories expounded in this book provided a broad base for bringing forth the Hand Mirror. Dealing with essential matters of the Seon school in the form of questions and answers, the book consists of six sections: “Three Saints,” “A Dialogue between the Two Sages,” “A Supplement [to the Dialogue],” “An Exposition by a Foolish Man,” “Mountain Cloud,” and “Three Statements of Yunmen.” Among these, the first two sections contain dialogues between Elder Ch'ŏngp'ung 淸風 (d.u.) and Venerable Howol 皓月 (d.u.) about the relationship of the Three Statements, Three Mysteries, and Three Essentials in Linji Chan. The third section generalizes the matters discussed in the previous sections, thereby attempting to reveal Linjiʼs intention that "Each Statement must comprise the Gates of the Three Mysteries, and the gate of each Mystery must comprise the Three Essentials. There are expedients and there is functioning." (T 48.301c–302b) The fourth section is a discourse in which a master who calls himself a foolish man responds to a monkʼs request to deliver him more instructions first by giving him a shout. In the section, the master then answers the monkʼs questions with the help of such notions as illumination and action, guest and host, temporal and real, and the Four Classifications. The fifth section briefly traces the origin of the Three Statements of the Yunmen school. The final section summarizes the Three Statements of Linji and Yunmen and then concludes with the remark that pursuing words only ends up with the seeker picking up scraps of scriptures, while grasping the real meaning in mind leads to the definite gate. On the detailed information on this text, see Jeong, Yeongsik 정영식. 2010. “Samhyeon samyo ui gaenyeom e daehan gochal” 三玄三要의개념에대한고찰 (An Investigation on the Concepts of the Three Mysteries and Three Essentials). Han-guk Seonhak (Journal of Korean Seon) Vol. 25; Ko, Ikchin 고익진. 1979. “Baengnyeonsa ui sasangjeontong gwa cheonchaek ui jeosulmunje”白蓮社의思想傳統과天頙의著述問題 (The Thought Tradition of Baengnyeon Temple and Problems about Cheonchaekʼs Authorship). Bulgyo hakbo 16.