What is the meaning of the sentence "The mountain is in harmony with heaven and earth, and you dare to leave the king"?

This is Wei Zi's sweet words to Erkang in Princess Zhu Huan. In fact, its origin comes from "Shang Ge" in Yuefu Poems, with the title "Shang Xie" and the full text: Shang Xie! I want to know you and live a long life. I long to know you, long live, this heart will never fade. Thunder in winter, rain and snow in summer, harmony between heaven and earth, but dare to break with you.

"I dare to leave you when the mountains are in harmony with heaven and earth" means: when the mountains are flat and the ground collapses into one, I will leave you. It means swearing to love, love is stronger than gold!