From which aspects does Mo Ren Tao Fu introduce Fu Tao in turn?

Spring Festival couplets originated from the word peach, but they cannot be equated with the word peach. After ancestors realized Fu Tao's function of praying for disaster, Fu Tao appeared frequently in festivals. At first, I portrayed the image of Er Shen, but after all, not many people have a good artistic foundation. Later, for the sake of simplicity, I simply wrote the words Shen Tu and Lei Yu. But it is too monotonous to write only these words every year, so some people began to try to write two auspicious words. At least in the Tang Dynasty, we can see the auspicious words of "beginning of spring Day, Book Gate" from Dunhuang Scriptures. After the maturity of modern poetry, it has gradually become a habit to adjust the levelness in poetry creation. Considering the shape of the gatehouse and the influence of the idea of "symmetry and unity" since ancient times, it is natural that some people will think of turning auspicious words into symmetrical literary opposites. Around the Five Dynasties, Meng Chang, a master of the post-Shu Dynasty, wrote "Qing Yu Jiajieno in the New Year". Changchun is the earliest known Spring Festival couplets.