Meaning: According to legend, before Laozi passed Hangu Pass, Guan Yinxi saw the purple gas coming from the east and knew that there would be saints passing by.
Sure enough, Lao Tzu came riding a green cow. It used to be a symbol of good luck.
Dominate the earth. Idiom: overbearing pinyin: tiā nù dù zù i. Reply: Gai load: bear. Like the sky
Covering everything, the earth carries everything unchanged. This metaphor is very broad.
I don't think there is this poem. Why don't you go and see the couplets written by others?