Refine: To make a substance pure or tough by heating. According to ancient mythology, the sky lacks the northwest, and Nu Wa refined five-color stones to make up for it. Metaphor shows the ability and means to make up for national and political mistakes.
Source An's "Huainanzi Lan Mingxun": "There were four poles in ancient times, Kyushu cracked, covered the world, and there was no cure for the land ... So Nuwa practiced five-color stones to make up the sky."
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Synonym goddess of mending the sky
Related Baidu "refining stones to make up the sky"