Wu Zetian pressed her tongue with wood to express her regret. When Wu Zetian was in power, she was tough. When she treats prisoners, she will directly put wood into their mouths, and prisoners can't defend themselves.

Tongue suppression is an ancient superstitious behavior. In ancient times, people thought that people would go to the underworld after death, so they had to put something in their mouths, so that when they arrived in the underworld, they would not talk nonsense, make the Yan angry, suffer less, and be reborn into a good family in the next life.

At the same time, the tongue depressor has many uses. When you go to the underworld, you can eat your mouth directly when you are hungry, and you can also bribe the underworld with your mouth, so things are much more convenient. Some people even say that putting jade in your mouth can prevent the corpse from rotting.

In ancient times, the position of "tongue-pressing" in people's minds was the same as that of those who were buried in search of a treasure house of geomantic omen. The richer the family, the more expensive the "tongue-pressing" things will be, while ordinary people don't have so many valuable things, so they can only enlarge their meals in their mouths.

Wu Zetian, as the female emperor in the history of China, only put a piece of wood in her mouth, which puzzled many people. Finally, people discovered the secret, and Wu Zetian did it to repent.

When Wu Zetian was in power, she was very strict with prisoners. Not only does she often take it out on prisoners, but she also punishes them cruelly. When she is in a bad mood, the prisoner will be very scared. When she was in power, no one listened to her, so when she saw a prisoner, she would put wood in the prisoner's mouth to make the prisoner stop talking, so as to relieve her anger.

In her later years, Wu Zetian was afraid that she was sinful and would not have a good result in the underworld. So she used wood to "press her tongue" to repent and relieve psychological pressure.