釋鑑稽古略續集 2.69

2.69

洪武正韻　上以舊韻起於江左。多失正音。乃命學士樂韶。以中原雅音校正之。書成。詔頒行之。

Hongwu Zhengyun: The Emperor considered that previous rhyme books originated south of the Yangtze and largely lost the correct pronunciation. He thereupon ordered the Academician Le Shao to correct them using the elegant standard pronunciation of the Central Plains. When the book was completed, an edict was issued ordering its distribution and implementation.