I think you must have seen it in the second paragraph of Mencius Liang Wang Hui.
The specific content is:
Mencius saw Liang grazing elk in the swamp, and said, "Do saints enjoy it?"
Mencius said to him, "A saint is happy when he has it, and a saint is happy when he has it. The poem says:' After the beginning of Lingtai, Shu Ren attacked the Jingtai camp, which lasted for several days. Don't be anxious from the beginning, the common people will come. Wang Zailing, Rufen Fuyou, Rufen Zhuozhuo, Bai Niao Crane. Wang is in Lingnuma. He jumps into the fish. "King Wen takes the people as the platform and the swamp as the land. When people are happy, they call it platform Lingtai, swamp spirit powder, elk, fish and turtle, and they are happy. The ancients enjoyed themselves with the people, so they could enjoy themselves. Tang Shi swears, "Time is killing you? Give it to the woman and die together. "People want to die with them. Although there are birds and beasts in the pool, how can they enjoy themselves?"