《太平广记·卷四百二十四·龙七》
他带着这些青泥在市肆间寻访，偶然被一个作买卖的胡人看见了，胡人吃惊地说： 这是龙的食物，是从哪弄来的？ 
以访市肆，偶胡贾见。惊曰： 此龙食也。
He took the mud and traveled to the market, where he was seen by a Hu merchant, who was surprised and said: This is dragon food. Where did you get it?