In couplets, the word "rich" in the first couplet is missing for no reason, and the word "chapter" in the second couplet breaks the word "day". If it is written by other ordinary people, there is a great chance of making mistakes. But this couplet was written by Ji Xiaolan, and it has been publicized since the Qing Dynasty, so the probability of making mistakes is almost zero. When looking up the writing rules of simplified and traditional Chinese characters, "Fu He Zhang" doesn't have such short arms and legs or gild the lily, but it happened that Ji Xiaolan couldn't have made such careless writing mistakes, so it can be speculated that this couplet for Ji Xiaolan was intentional.
Because it was written in front of Confucius' house, Ji Xiaolan, who is well-read and versatile, dare not say that his literary attainments can compare with Confucius, an old gentleman. Naturally, Ji Xiaolan would unconsciously show his admiration for Confucius. Just like these two words, the word "rich" means that Confucius is "rich and headless", and the word "Zhang" means that the article reaches the sky at the end, which is entirely an opportunity to praise Confucius. Of course, it is not surprising that this is also a word game played by the ancients.
Secondly, Confucius was highly respected by Ji Xiaolan, and Ji Xiaolan compared Confucius with "headless wealth, soaring literature", but he did not express his grand ambition in the same way. Then, since this poem is not only a tribute to Confucius' merits, but also an expression of his thank you sir, how can it be mistaken as a typo?
Secondly, in the development of Chinese characters, the word "fu" has actually appeared less, and the word "Zhang" has also become popular, but it has gradually been abandoned in the later development process. This kind of writing is a vulgar writing. Song Sijia Calligraphy Dictionary contains 15 "fu", among which eight "fu" are slightly less. It can be seen that at that time, this kind of writing was highly respected among literati. Although it seems to be a typo today, it was an unconventional calligraphy style among literati in ancient times.
In addition, Emperor Qianlong loved China culture. Although he says that calligraphy is not accomplished, he also knows how to write some fonts. Among them, Ji Xiaolan was treated with courtesy. Ji Xiaolan was able to write this work, and Emperor Qianlong must have known it, and Ji Xiaolan must have explained it more at that time. For these two blatant typos, Emperor Qianlong didn't say anything, so servants in general naturally didn't dare to comment. These two words can naturally be handed down, and no one has abolished them until today.