Why is Guanyin Bodhisattva said to be Tang Monk’s great disciple?

Avalokitesvara Bodhisattva turned into a scabies wandering monk and presented his tin staff and cassock to Taizong. Taizong gave it to Xuanzang. Avalokitesvara came to the stage and spoke to Xuanzang about the wonders of Mahayana Buddhism. Xuanzang was willing to go to the Western Heaven. Taizong named him the "Royal Disciple Holy Monk" and gave him the title "Tripitaka". Sanzang Tang Monk left the customs.

Avalokitesvara went to the East to search for sutras on the orders of the Buddha. By chance, he met the Tang Dynasty king who built a water and land conference. The person who lectured on sutras was none other than Master Xuanzang. So he deliberately took out the brocade cassock and the nine-ring tin staff and sold them at a very high price, but no one bought them. The king of the later Tang Dynasty wanted to buy it as a gift to Xuanzang, but the Bodhisattva said that he was willing to give it to someone he was destined to meet.