What is the explanation for the word "manchu" in the sentence "Sighing one after another is barbaric, looking back to make mistakes" in Nalan Rongruo's poem "Man Ting Fang Fang, Snow and Crows Turning

What is the explanation for the word "manchu" in the sentence "Sighing one after another is barbaric, looking back to make mistakes" in Nalan Rongruo's poem "Man Ting Fang Fang, Snow and Crows Turning Crows"?

Barbaric touch: a metaphor for two parties quarreling over trivial matters.

Fable: In ancient times, those who established a country on the left corner of a snail were called the Chu clan; those who built a country on the right corner of a snail were called the Man clan. The two barbarians often fought over territory, leaving tens of thousands of corpses. See "Zhuangzi Zeyang".

Song Dynasty Su Shi's "Lotus Sutra Collected by Wang Jinqing": "I know that the horn of a snail can fight against barbarians.