《贞观政要·卷一·论君道》
皇上作为万圣之尊，高贵得与天地同辉，如果只极力推崇天命，让自己长命百岁，全然不思考居安思危的道理，力戒骄奢，崇尚节俭，推崇好的德行，而只任自己的情欲蔓延而不加以克制，这就像砍掉树根来让树木枝繁叶茂，堵塞源头而想让河水流得很远的道理一样。
人君当神器之重，居域中之大，将崇极天之峻，永保无疆之休。不念居安思危，戒奢以俭，德不处其厚，情不胜其欲，斯亦伐根以求木茂，塞源而欲流长者也。
As the supreme saint, the emperor is as noble as heaven and earth. If he only tries his best to promote the destiny and make himself live a long life, he does not think about the truth of living in peace and thinking about danger, abstaining from extravagance, advocating frugality, and promoting good virtues, but only letting his desires spread and not restraining them, it is like cutting down the roots of trees to make the branches luxuriant, blocking the source and wanting the river water to flow very far.