What is the meaning of "giving Yan Zhai" seal in Qing Dynasty? Why do many famous books have Yan Zhai's seal?

In Qing Dynasty, the Yi Dynasty in Ninghua made a village in the east. With the word "Hou", the official is a scholar and the official is a doctor of punishments. Gong Shi has a record of giving an inkstone to Zhai.

Yichaodong

[Qing] (1729- 1807) was born in Ninghua, Fujian. He was born in the seventh year of Emperor Shizong of Qing Dynasty and died in the twelfth year of Emperor Renzong of Qing Dynasty at the age of 79.

In the thirty-fourth year of Qianlong (AD 1769), he was a scholar. Li was transferred to the doctor of punishments, and he was diligent and fair. After the official to the minister of Guanglu Temple. Chao Dong, with little education, studied under Zhu Xi and was called by Cai Shiyuan, especially in the name of poetry. He has written four volumes of poems and notes for Yan Zhai, and eight volumes of poems and notes "South Window" are all parallel to the world.