"This hatred lasts forever" comes from the last two sentences of Bai Juyi's "Song of Everlasting Sorrow":

I would like to be a winged bird in the sky, and a twig on the ground.

The eternity of heaven and earth will eventually come to an end, and this hatred will last forever.

"From now on Xiao Lang is a passerby" comes from "Giving a Maid" by Cui Xiao of the Tang Dynasty:

The princes and grandsons follow in the footsteps,

The green beads are dripping with tears. towel.

As soon as Hou Men entered the sea,

Xiao Lang was a passerby from then on.

And "Since ancient times, passion has left room for hatred, and this hatred lasts forever" is spelled out by another sentence, which was quoted in "Journey to the West" and became Zhu Bajie's famous saying.