It is original work by Mr. Gu Long.
Source: 1. The original text of Mr. Gu Long’s calligraphy: When people are in the rivers and lakes, they can’t help themselves. They fight for every inch of their lives and forget about life and death.
2. The only one in Gu Long’s “People in the Jianghu” series In the movie "The Sword of the Third Young Master", Yan Shisan made a similar statement, which may be the prototype of this sentence.
3. "Midnight Orchid" from "The Legend of Chu Liuxiang"