《太平广记·卷七十四·道术四》
第二天早晨，天快亮的时候，俞叟对吕生说： 你应当赶快回去，王公很快就会召你去了。 
明旦，天将晓，叟谓吕生曰： 子可疾去，王公旦夕召子矣。 
The next morning, when the sky was about to get light, old Mr. Yu said to Lü Sheng: You should rush back quickly, the prince will soon summon you.