Which disciple of the Tathagata is Tang Priest?

In the novel The Journey to the West, Tang Priest's young father was killed by a river thief and his mother drifted him away from the river, so he was called Jiang Liuer.

Tang Priest, a second disciple of the Tathagata in his previous life, was demoted to the lower bound by the Tathagata because of his neglect of Buddhism. Under the guidance of Guanyin Bodhisattva, he went to the Western Heaven, not far from Wan Li, to learn Buddhist scriptures at the behest of Emperor Taizong. On the way, I received three apprentices, the Monkey King, Zhu Bajie and Sha Wujing. After eighty-one difficulties, he finally got the true scriptures, returned to the Tang Dynasty, and was crowned as the "Buddha of Tan Gongde" by the Tathagata Buddha.

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The birth of Tang Priest:

The Tang Priest in Journey to the West was reincarnated as Elder Jin Chan, the second disciple of Tathagata. He is a posthumous child. Because of his parents' tragic and bizarre experiences, he grew up in a temple, became a monk in Jinshan Temple, and finally moved to a famous temple in Beijing to practice.

Tang Priest is studious and highly savvy, and stands out among the monks in the temple. Emperor Taizong invited him to hold a "land and water conference" and was elected as a monk by Guanyin Bodhisattva. Became sworn with Emperor Taizong and went to the Western Heaven to learn Buddhist scriptures.