Customs clearance documents are the credentials of officials (envoys) traveling to other countries in ancient society. They were once called talisman, festival, degree certificate, road certificate, etc. They are an important basis for proving the identity of the envoy. Of course, in modern society, the name "Customs Clearance Document" has long been replaced by passport. However, in ancient society, when the economy and communication were underdeveloped, the Customs Clearance Document was a pass for passing through customs, and it needed to be stamped every time you entered a country. The seal of the country is used to prove that the envoy has been to this country, and its role cannot be underestimated.

Not having a customs clearance document is equivalent to losing your passport abroad. You will not be able to prove your identity, and you will be detained in that country and will not be released. Well, it was the same in ancient times. Even in ancient society, it was even more dangerous than now. Not only will your identity as an emissary be doubted and your emissary power will be deprived of you, but you may also be regarded as a spy or a liar. If you get convicted and imprisoned, if you don't do it right, your head may be in a different place and your bones may be buried in a foreign country!

For example, we are all familiar with "Journey to the West". In it, Tang Monk and his disciples traveled thousands of miles from the Eastern Tang Dynasty to the Western Heaven to worship Buddha and seek scriptures. All the countries they passed along the way had to pass customs clearance. The ultimatum, there was even an episode where Master Tang Seng and his disciples had obviously escaped, but they returned again because the ultimatum to pass the customs was left behind. Why did Tang Seng and his disciples pay so much attention to customs clearance documents? It is because the customs clearance document witnessed the entire journey of Tang Monk to the West to obtain Buddhist scriptures. It contains the signatures and seals of kings from many countries. It records the entire journey of the four masters and apprentices, and also carries the hardships they experienced along the way.

When Tang Monk and his disciples returned to the Tang Dynasty, what could they use to prove to Tang Taizong that they were going to the West to obtain scriptures? They had to prove it through this customs clearance document and the seals of the kings in it. Because the scriptures can be forged, the records on the customs clearance documents cannot be forged. If the customs clearance documents are lost, think about the consequences. It will be that all your hard work has been wasted, and you will be left unable to defend yourself. The situation of criticism.