as solid as a rock
... 安如泰山 = as secure as Mount Taishan 安如泰山 = as solid as a rock 安如磐石 = as solid as rock ...
安如泰山,汉语成语,拼音是ān rú tài shān,意思是形容像泰山一样稳固,不可动摇。出自《上书谏吴王》。