《魏书·列传·卷九》
别人又劝他说： 殿下的儿子媳妇已经渡过黄河，两边互相不知道，现在低头自感安全，不是很危险吗? 
又说曰： 殿下兒妇已渡河，两头不相知，今俯眉自安，不其危乎！ 
Another person said to him: Your Highness's son and daughter-in-law have crossed the Yellow River, and the two sides do not know about each other. Now that you are feeling safe, aren't you in great danger?