《魏书·列传·卷四十八》
军队随驾，为的是保卫一国之主，哪里只是仅为仪容摆设呢，这是为了防备不测啊。
警跸于闱闼之内者，岂以为仪容而已？盖以戒不虞也。
The army is supposed to accompany the emperor in order to protect the ruler of a nation, rather than acting as bodyguards for personal appearances. It's a precaution against the unexpected.