A sign of male maturity, did ancient men have to grow beards?

Yes, because the ancients thought: "The parents who suffer from skin damage dare not do so, and filial piety begins."

During the Zhou and Jin Dynasties, people attached great importance to beards, and thought that body protection and hair care were the foundation of filial piety and could not be damaged. Therefore, the hair is generally washed and not combed, and it is allowed to break naturally, and both men and women pile it into a bun on their heads.

"The Book of Filial Piety" says: If the body and skin are damaged, the parents who suffer from it dare not damage it, and filial piety begins; Standing on the street, making a name for yourself in later generations to show your parents, is also the end of filial piety. The earliest historical records began in Zhou Gongdan. From the Han Dynasty to the Jin Dynasty, due to the popularity of Confucianism, the concern for the body and skin was raised to a very high moral level.

Extended data:

After the Revolution of 1911, great changes have taken place in men's hairstyles, costumes, social etiquette and customs in China. Men's haircut and shaving have become a part of daily life. However, many manners about growing a beard are still worth learning. For example, the younger generation doesn't have a beard in front of their elders, which is the embodiment of China's traditional cultural consciousness and ethics.

Generally speaking, when the father dies, the son should keep the beard of the upper lip and don't pull it out; When the mother dies, the son will leave a beard on his lower lip (chin). If you have no parents, you will have a beard on your lips. The so-called "storing ambition" is also true.

Kangxi Dictionary in Qing Dynasty also made a clear definition of the names of various beards. The beard of the upper lip is called moustache, the beard of the lower lip is called moustache, the beard next to the cheek is called moustache, and the beard on the chin is called moustache. Each part has a different name, and a handsome man can also be said to be an aesthetic of the ancients for beards.

References:

Baidu encyclopedia-beard

Baidu encyclopedia-body hair and skin, influenced by parents, dare not damage.

Baidu Encyclopedia-Why did the ancients grow beards when they were adults, especially literati and officials?