According to the book Traditional Vietnamese Prayers - Culture and Information Publishing House, tomb sweeping is one of the beautiful and long-standing traditional cultural features of the Vietnamese people. In addition to showing gratitude and respect for the deceased, cleaning and repairing the graves as well as offering offerings is to invite ancestors to celebrate Tet with their descendants.
Tomb-sweeping is usually done from after Ong Cong Ong Tao Day (December 23) until the afternoon of the 30th of Tet or the afternoon of the 29th of Tet if it is a short month.
According to folk beliefs, people visiting graves should avoid the following things to avoid bad luck:
Avoid visiting graves in the late afternoon.
Tomb sweeping should be done in the morning or on nice days. Avoid visiting graves on cloudy days or late evening (after 3pm) to avoid bad air and evil spirits that can affect health.
Avoid visiting graves while menstruating or pregnant.
Women who are menstruating or pregnant should not visit graves. This is because their immune system is weak and they are susceptible to cold air. Visiting graves can have a negative impact on the health of the mother and fetus.
Avoid talking loudly or joking when visiting graves.
Absolutely do not joke, laugh loudly, or have an unserious attitude when visiting graves because this is a solemn place with many spiritual meanings. Laughing and joking are considered disrespectful to the deceased.
Avoid calling each other's names when visiting graves.
While making offerings and reading prayers to visit graves, avoid calling each other by name. According to ancient beliefs, if the spirits know the name of a living person, they can follow him home or bring bad luck to that person.
Avoid taking pictures at graves.
The main meaning of the tomb-sweeping festival is to express gratitude and invite ancestors to celebrate Tet with the family. Therefore, you should not stand in a row in front of the grave to take group photos or pose inappropriately because it can offend the ancestors, thereby encountering many unlucky and undesirable things.
However, activities during the ceremony such as cleaning and wiping the grave... can still be photographed naturally.
Avoid stepping on other people's graves.
When visiting graves, be careful not to step on, trample on, or kick offerings on other people’s graves. This shows disrespect to the deceased and will cause your family to encounter bad luck and misfortune after the grave-sweeping day.