In "Journey to the West", Tang Taizong Li Shimin personally hosted a banquet to entertain Tang Monk, and gave Tang Monk some more important personal belongings. In addition to the purple gold bowl used for the transformation of fate, Li Shimin also personally gave Tang Monk a very important identity certificate, that is, the so-called Customs Clearance Document. On the way west, Tang Monk was very careful to protect this customs clearance document, the first thing to do every time he went to a place was to hand it over to the local king for stamping, and in the 13 countries that Tang Monk traveled west, the king of each country did not dare to embarrass Tang Monk after seeing this document, so what was written on the Tang Monk's customs clearance document?
In fact, when Li Shimin gave Tang Monk this customs clearance document, he fully considered the various difficulties that Tang Monk might encounter on the road, so he first wrote 6 big characters on the first page of this customs clearance document: "Tang Dynasty under the imperial gift." This shows that the identity of the Tang monk was approved by the Tang Emperor, which is equivalent to the identity certificate of the Tang monk, and in that era without an identity card, this customs clearance document was the only thing that could prove the identity of the Tang monk, so the Tang monk had to protect it well along the way.
Secondly, Li Shimin clearly stated his 3-point attitude in this customs clearance document: First, Tang Monk went to the Western Heavens to learn the scriptures on behalf of Tang Taizong Li Shimin, and other countries must not embarrass him; Secondly, the Western Heavenly Scriptures are going at the will of Guanyin Bodhisattva, and once the Tang monks have any mistakes in your country, be careful that they are condemned by heaven; Third, the Tang monks took the scriptures from the Western Heavens at the behest of my Tang Dynasty, and if you don't give datang face, then you will blame datang for doing something to you.
Since the influence of Datang spread to all parts of Asia at that time, the 13 kings encountered by Tang Monk on the way west naturally did not dare not give Tang Face, and their attitude would take a big turn of one hundred and eighty degrees after seeing Tang Monk's customs clearance documents. Because once the Reception of Tang Monk is not good, when Tang Monk returns to Li Shimin to report to work, Datang will definitely find trouble for his own country. To put it bluntly, the military strength of the Tang Dynasty was an important guarantee that Tang Monk could safely go to the Western Heavens to learn the scriptures.
In order to highlight the status of the Tang monks, Li Shimin also personally declared in the document that the Tang monks were his own imperial brothers, and because they were instructed by Guanyin Bodhisattva, they went to the Western Heavens to obtain the True Scriptures. Therefore, many countries do not dare to despise the identity of Tang Monk, after all, he is li Shimin's imperial brother, once something goes wrong, he can not bear the responsibility, after seeing this customs clearance document, he can only serve Tang Monk with good water and good tea.