《水经注·卷六》
蔡伯嘈对卢子干、马日禅说：我为天下人写的碑文很多，自己却感到有点惭愧；只有为郭有道写这篇碑文，可以毫无愧色。
蔡伯喈谓卢子干、马日磾曰：吾为天下碑文多矣，皆有惭容，惟郭有道，无愧于色矣。
Cai Bechao said to Lu Zigong and Ma Rizhan: I have written many epitaphs for people around the world, and I felt somewhat ashamed; Only the epitaph I wrote for Guo Youdao can I be fearless.