法苑珠林 28.48

28.48

地鏡圖曰。視屋上瓦獨無霜其下有寶藏晏子春秋曰。和氏之璧井里之朴耳。良工修之則為存國之寶（孔鄉子云井里之厥又云玉人琢之為天下寶）。

The Dijingtutu says: If one observes that among the tiles upon a roof, only some have no frost, underneath them is a hidden treasure. The Yanzi chunqiu says: The jade disk of the He clan was merely an unworked stone from a hamlet; if a skilled craftsman refines it, it becomes a treasure that preserves a state (Kongxiangzi says, 'an unworked stone from a hamlet'; he also says, 'if a jade worker carves it, it becomes a treasure of the realm').