《徐霞客游记·粤西游日记十》
于是向北出了后洞。洞右壁外面的山崖之上，石窍裂开，岩石如奇葩高悬，云状的石棱凌乱不堪。
七人即《壶天观铭》所题名字，在栖霞者，其岁月俱为乙未二十八日。
So I went out of the back cave to the north. On the cliff outside the right wall of the cave, there was a crack in the stone hole, the rock hung high like a strange flower, and the cloud-like stone ridge was in chaos.