空口无凭， 立字为证。

Words of mouth being no guarantee, a written statement is hereby given.

兹证明此纸持有人拥有良心一颗，质地良好，尚未泯灭，空口无凭，立此字据…

This is to certify that the holder of this paper is in possession of a fine heart of quality texture which is not yet eaten up by any dog male or female …