一个小笑话,帮我理解一下

A STATESMAN who had been indicted by an unfeeling Grand Jury was
arrested by a Sheriff and thrown into jail. As this was abhorrent to his fine spiritual nature, he sent for the District Attorney and asked that the case against him be dismissed.
一个政治家被无情的大陪审团起诉了，被州长抓进了监狱。这对他的精神造成了打击，他给检查官写信，要求撤诉。
"Upon what grounds?" asked the District Attorney.
“有什么理由呢？”检查官问
"Lack of evidence to convict," replied the accused.
“证据不足。”被千说
"Do you happen to have the lack with you?" the official asked. "I should like to see it."
“你有证据证明你清白吗？”官员问“我要确实看到证据”
"With pleasure," said the other; "here it is."
“当然有”，其他人说，“在这里呢”
So saying he handed the other a check, which the District Attorney carefully examined, and then pronounced it the most complete absence of both proof and presumption that he had ever seen. He said it would acquit the oldest man in the world.这样说着，被告递给了别人一个支票，检查官仔细检查了下，然后