《徐霞客游记·游嵩山日记》
洞有二丈深，宽不到二丈，是达摩面壁九年的地方。洞门下对少林寺，正对少室山。
洞深二丈，阔杀之即宽度不及深度，达摩九年面壁处也。洞门下临寺，面对少室。
The cave is two zhang deep and less than two zhang wide. It was where Bodhidharma sat facing the wall for nine years. The cave’s entrance faces Shaolin Temple and Mount Song.