《旧唐书·列传·卷三十》
大鱼依靠巨海，神龙凭据江河源泉，这是说人君不可以轻易地远征。
大鱼依于巨海，神龙据于川泉，此谓人君不可轻而远也。
Big fish rely on the great sea, and divine dragons depend on the source of the river, this is to say that a ruler should not lightly go on a distant expedition.