《资治通鉴·唐纪·唐纪二十四》
武则天的灵柩将要与唐高宗李治合葬于乾陵，给事中严善思上疏认为： 乾陵墓穴的门是用石头做成的，石门的门缝又用熔化的铁水密封，如果想打开石门，就必须使用钻凿一类的工具。
太后将合葬乾陵，给事中严善思上疏，以为： 乾陵玄宫以石为门，铁锢其缝，今启其门，必须镌凿。
Wu Zetian's coffin was going to be buried with Emperor Gaozong of Tang, Li Zhi, at the Qianling Mausoleum, and the acting imperial censor Yan Shansi submitted a memorial to the emperor saying: The gate for the tomb at the Qianling Mausoleum has been made of stone, and the crack in the stone gate has been sealed with molten iron. If you want to open the stone gate, you must use a tool such as a drill.