《论衡·卷三十·自纪篇》
如果文章的成熟总是要对贤人有所仿效，这就等于说醴泉必然出自旧源，嘉禾必然发自老根。
文孰常在有以放贤，是则泉有故源，而嘉禾有旧根也。
If an accomplished literature must always depend on an imitation of the ancients, that would amount to saying that the cordial spring always flows from an old source, and that fine wheat always springs from an old root.