《论衡·卷二十七·定贤篇》
自汉文帝赞赏虎圈啬夫，斥责上林尉以后，张释之举周勃、张相如为例，汉文帝因此才醒悟。
夫自文帝尚多虎圈啬夫，少上林尉，张释之称周勃、张相如，文帝乃悟。
After Emperor Wen of Han praised the Tiger Keeper Hu Quan, while reprimanding the Upper Park Clerk, (Zhang) Shizhi cited Zhou Bo and Zhang Xiangru as examples, Emperor Wen then awakened.