Stone reverse reads:
''Rest well in the cool (place) for only a short while. The curtain is about to arise on the approaching eternity*, then you shall appear, with skin and bone**, before the chair of the Lamb."

Note:
* The German literally translates closer to "it will soon play the act, the approaching eternity" but this is awkward and difficult to understand.
** I believe "skin and bone" alludes to the body of the deceased being resurrected, like Christ, with incorruptible flesh."