Were there Hui people in ancient times?

Of course, the formal formation of the Hui nationality was in the Yuan Dynasty.

Hui nationality is the most widely distributed minority in China, and there are mosques in places where people live in concentration, also known as worship temples. In the middle of the 7th century, a large number of Persian and Arab businessmen came to China coastal cities such as Guangzhou and Quanzhou by sea and land, and settled in Chang 'an and Kaifeng in the mainland. /kloc-in the 3rd century, the Mongolian army marched westward, and a large number of people from the western regions moved to China, absorbing ethnic elements such as Han, Mongolian and Uygur, and gradually forming a unified nation-Hui.