Why does the introductory chapter mean to look forward to a son?

The introductory chapter comes from Nongzhang and Nongwa, which represents people who are officials. In ancient times, it meant giving birth to a son. Using this word to name someone means looking forward to a son.

The "Zhang" in the ancient names is most likely the same as "Zhang", and "Zhang" comes from a common idiom among the ancients: "Nongzhang Nongtile". In fact, "Zhang" is a kind of jade article. In ancient times, people would wear jade articles like "Zhang" on boys, hoping that the boy would grow up to be a gentleman, so "Nong Zhang" means giving birth to a son.

"Wa" refers to spindles, because spindles were made of clay in ancient times, and clay products are collectively called "tiles". The ancients would give spindles to girls to play with, hoping that she would learn to spin and become a virtuous and virtuous housewife, so "making tiles" meant giving birth to a daughter.

Extended meaning:

"Nongzhang and Nongtile" are derived from "The Book of Songs·Xiaoya·Siqian", "A man is born, a bed to sleep on, and clothes to wear." "Zhang is the place where women are born, the clothes are carried, and the tiles are used for carrying the work." The tiles are the parts of the spinning wheel. Boys playing with Zhang and girls playing with tiles reflect the expectations of parents for their children in ancient times.

The distinction between "sleeping on the bed and Nongzhang" and "sleeping on the ground and Nongtile" still existed in disguise during the Republic of China. In some places, the birth of a boy is called "Da Xi", and the birth of a girl is called "Xiao Xi". Relatives and friends present colorful tents and wedding couplets, and men are called "Nong Zhang" and women are called "Nong Wa".