First of all, let's have a question, why is the prototype of Jiang Ziya in mythology called Taigongwang in history? If you don't know, then take a look at the record in the "Historical Records": "Taigong looked at Lu Shang, and the people of the East China Sea ......."On the occasion of Yu Xia, it was sealed in Lu, or sealed in Shen, whose surname was Jiang, and was called Lu Shang ...... from his surnameZhou Xibo hunted, and when he met Taigong Yu Weizhiyang, he said with words, saying: Since my ancestor Taigong said, when there is a saint suitable for Zhou, Zhou Yixing, the son is really evil. My Taigong has been looking forward to his son for a long time, so the name is called Taigongwang. ”
Understood, King Wen of Zhou's father (Ji Taigong) foresaw that a saint was coming to Xiqi, and the Zhou Dynasty would prosper because of it, and Ji Taigong had been looking forward to it for a long time, but he couldn't wait for the saint to appear. Therefore, when King Wen met Jiang Ziya, he respectfully called him Taigongwang, which means the person that Taigong Ji is looking forward to. Jiang Shang assisted King Wen and King Wu, and made great contributions in the process of destroying Shang and Xingzhou, and was sealed in the State of Qi. There are many stories and legends about him, and he was written into "The Romance of the Gods" by later generations. In "Romance of the Gods", many dead characters were canonized as gods by Jiang Taigong, so there is an old folk saying, "Jiang Taigong is here, and the gods abdicate!" When the gods from all walks of life saw Jiang Ziya, they had to avoid it. There is also an old saying, "Mrs. Jiang is here, there are no taboos", what does it mean? 
Jiang Taigong and Miso Let's first look at the relevant customs of Jiangsu and Zhejiang regions in history. According to the records of the "Qing Barnyard Banknotes", during the Qianlong period, people in Jiangsu and Zhejiang liked to spread sauce when eating puffer fish. When making sauces in the summer, people will put a large letter on the door of the hall house, "Jiang Taigong is here", which means to ward off evil spirits and get good luck. The outsiders didn't understand what they meant, so they consulted the famous Qiantang literati Yuan Mei. Yuan Mei said with a smile, "This means that Jiang Taigong is not good at leading troops, but he is good at generalizing sauce (general)!" Although Yuan Mei is joking, the ancients believed that sauce is the first of all flavors, such as Yan Shigu's "Urgent Chapter" has a saying, "The sauce person, the general of all flavors, the sauce leads all flavors." Over time, the words posted on the door by the people of Jiangsu and Zhejiang added the words "no taboos". Not only make sauce, but also post other things at home. It seems that Mrs. Jiang is busy enough, not only in charge of the sauce, but also in charge of all kinds of big and small things. With Mrs. Jiang here, people don't have to be taboo about anything, and everything goes smoothly. The Qing Dynasty's "Tales of the Garden" also has the same record, "Today, the south cooks fish and meat, all use sauce, so no matter how big or small the portal, when the dog days, each family must make their own and take their convenience." When making sauce, the five words "Jiang Taigong is here" must be written, which is to win and be everywhere. ”
Obviously, it is too much to put Jiang Taigong in charge of the quality of the sauce. "Jiang Taigong is here, there are no taboos" There is a more formal statement. Since Qin Shi Huang, the emperors of all dynasties have to sacrifice the famous mountains and rivers and the eight gods, the eight gods are the eight gods (God, landlords, soldiers, etc.), according to the "Historical Records and Feng Zen Book" records, "the eight gods will be, or said to be made since the Taigong", it is said that Jiang Taigong is divided. Ancient books such as "Taiping Yulan" mentioned that the gods of the four seas and Hebo were also sealed by Jiang Taigong, and Jiang Taigong once sent messengers to summon them in the name of the five gods, and the five gods were shocked. Therefore, in the Qing Dynasty's "Returning to the Fields", it is said that Jiang Taigong has been a god for a long time, "Today's people in every book on the portal 'Jiang Taigong is here, there are no taboos', and it is not without roots", which means that this is not without basis, after all, Jiang Ziya is the boss of the gods. 
The ancient strange book "Lu Ban Quanshu" is considered to be Lu Ban's posthumous work, which contains such a passage, "* After the opening of the mountain and logging, the heaven and the earth are unscrupulous, the years and months are untaboo, the day is unscrupulous, the upper is auspicious, Jiang Taigong is here, and the gods avoid it." "As long as there is Jiang Taigong's town, there will be no taboos when opening mountains and logging trees, and it will be auspicious. The ancient Taoist Qimen secret method also believes that "where the ground is broken and repaired, it can be written on yellow paper and pasted to the place where the soil is moved." The big character 'Jiang Taigong is here' in the middle, the right side is written 'Heaven and Earth Wuji', and the left side is written 'Yin and Yang Wuji and a hundred no taboos'". Strictly speaking, this is the most "authentic". 
The origin of the saying is in "The Romance of the Gods", Jiang Ziya once had a wife Ma, Jiang Ziya was not developed in the early years, Ma looked down on him and ridiculed him for not being able to achieve great things. When Jiang Ziya decided to go to Xiqi Yinxi, Ma refused to go to anything, and insisted that Jiang Ziya write a letter of resignation, and the two broke up. Ma remarried a poor man. Later, Jiang Ziya assisted King Wu to destroy Shang, and after the world returned to Zhou, Ma learned that his ex-husband had entered the prime minister, and he was extremely noble, and he immediately regretted it. Within a few days, Ma hanged himself. **In the ninety-ninth episode of "Jiang Ziya's Return to the Country and Sealing God", Jiang Zi named Ma as a broom star. 
The broom star symbolizes disaster, bad luck, and is also considered a "poor god". More detailed legends are recorded in the Yue Yan of the Qing Dynasty. It is said that after Jiang Ziya sealed the gods, all the gods were very satisfied, but the broom Xingma clan did not get an official position. Ma found Jiang Ziya and chattered endlessly to become a god. Jiang Ziya reprimanded her and said, "A woman's family, fighting for fame and fortune all day long, living like a poor god!" Jiang Ziya just said it casually, but Ma was very happy, and felt that the position of "poor god" was very good, so he left satisfied. As a result, wherever she went, the rich became poorer, and the poor places became even worse. People are complaining. Later, Jiang Taigong found out, gathered the gods, and wrote "Jiang Taigong is here, there are no taboos", so as to suppress the broom star. Since then, in order to avoid the poor god and avoid taboos, people have pasted "Jiang Taigong is here, there are no taboos" on the door and in the house, which has been handed down as a custom. Conclusion: There are other theories about the origin of this saying, which will not be repeated here. In our traditional calendar, there is a saying of "auspicious days of the zodiac", weddings, funerals, housewarming, etc., and there are often taboos of time. Whether Jiang Taigong can offset those taboos is unknown. You don't need to worry about this, just follow the local customs.