The four running script words on the plaque in the photo are from the right:
It is no wait
This plaque is in the fourth cave of Maijishan Grottoes , was written by the calligrapher Wang Wangwang in the early Qing Dynasty when he visited Maiji Mountain in Tianshui in his later years.
The four words "No Waiting" are taken from the scripture "Nama Maha Prajna Paramita is the Curse of No Waiting".
Hope this helps.