The weasel paid New Year greetings to the rooster, which was not a good intention.
In folklore, the weasel had no food to celebrate the New Year, so he stole food from the chicken's house by paying New Year greetings to the chicken. So people use this proverb to describe "pretending to be kind, but actually harboring evil intentions."
Origin:
It is said that after the creation of the ten heavenly stems and the twelve earthly branches, in order to facilitate people's memory and dissemination, the Emperor of Heaven found objects that were easier to understand. Coincidentally, there were 10 golden crows in the sky, so the Emperor decided to let them represent the ten heavenly stems, but the representatives of the twelve earthly branches were delayed and could not be determined.
At this time, someone suggested that the ten golden crows were all animals. It is only reasonable that the representatives of the twelve earthly branches are also animals. Why not let the animals in the world compete. The animals that arrive first serve as representatives of the twelve earthly branches. The Emperor of Heaven immediately made a decision, and the animals began to fight one after another. They were all safe at first, but during the fight, the weasel caught several mice and prepared to eat them.
The first is to replenish physical strength, and the second is to reduce competitors. The weasel did what he said. He didn't expect his behavior, but it frightened the chicken. The weasel hoped that the chicken would not grow, but the chicken did not give the weasel this face. The chirping made the mouse aware of it. The weasel couldn't catch the mouse and lost the game again, so he blamed the chicken and always wanted to take revenge on the chicken.
In order to prevent chickens from being wary, people habitually bow their hands in bows when meeting chickens. This is usually a ritual used during New Year greetings. This is the origin of "The weasel is not kind to the chicken when it wishes New Year greetings".