Liuliu Dashun is a common blessing language, hoping that everything will go well and all the best. There are several different theories about the origin of this statement.
One theory is that the 66 Shun originated from "Zuo Chuan". In "Zuo Chuan: Shi Jie's Admonition to Favor the State", there is a sentence of "Junyi, ministers, father's kindness, son's filial piety, brotherly love, younger brother's respect, and these numbers are tired of six shun". The meaning of this sentence is that the king should be benevolent, the courtiers should obey the etiquette, the father should be loving, the children should be filial, the elder brother should be fraternal, and the younger brother should respect the elder brother. These six relationships cover the six major events that people of all identities face and want to do in their lives, and they are all perfect, and they will definitely be "six or six smooth".
Another theory is that Liuda Shun originated from "Zhou Yi". In "Zhou Yi", the six hexagrams represent good luck and evil, and people hope that each hexagram is auspicious when divination, so they call the six hexagrams auspicious as the six great shuns.
There is also a saying that the June Six Shun originated from the liquor order. Some people speculate that because "six" is homophonic with "slip", "slip" is "smooth", so "six" is associated with "shun".
The above information is for reference only, there are many theories about the origin of Liuliu Dashun, and the specific source may vary depending on the regional, cultural and historical background. But in any case, the six major Shun is the expression of people's vision of a better life.