Before Tang Priest's departure, Li Shimin saw him off, and specially added some Chang 'an soil to his tea, in order to remind Tang Priest that he would rather love his motherland than other countries' two thousand gold. The Tang Priest also promised Li Shimin that he would return in three years and bring Mahayana Buddhist scriptures to the Tang Dynasty to educate all people.
On the way to learn Buddhist scriptures, between China and Tianzhu, there are Himalayas and the roof of the world. More than a thousand years ago, if people went to Tianzhu by land, they could only make a big circle, which would delay a lot of time. This road of seeking dharma thousands of miles away is full of difficulties and dangers. The real process of Tang Xuanzang's learning from the scriptures is not the state of journey to the west with his disciples. The truth is that Xuanzang travels alone most of the time, and he does everything alone. It can be said that it is a miracle to prevent bandits and find a way to eat and live, and it is difficult to fulfill his long-cherished wish to learn from the scriptures on the road.
It is a private act for Tang Xuanzang to go through the customs to learn from the scriptures. The government does not allow Xuanzang and others to learn from the West. They didn't get official approval. Going through customs without permission is punishable, and it is also treated as hooliganism. Xuanzang sneaked all the way and deliberately avoided the officers and men, which was time-consuming and laborious.
19 years later, Xuanzang returned to Chang 'an, and Li Shimin, Emperor Taizong, summoned him. The first sentence is: "Why didn't you report when the teacher went?" An obvious reprimand for questioning. Xuanzang replied: "When Xuanzang went, he played it repeatedly, but I sincerely hoped that it would be shallow and not allowed. It is a sin to do things in private, specializing in this, but deeply afraid. " In fact, Li Shimin doesn't care about Xuanzang's learning from the scriptures. For the need of political rule, Li Shimin attached importance to Buddhism.
When Xuanzang returned to China, he had reached the point where people were distracted, and his appeal was great. The ruler was also very sensitive to people's hearts. As a famous emperor, Emperor Taizong knew how to guide the people, win over the people and manage the Buddha well, so the people would naturally worship the great monarch and emperor.