'Matching social status' is an inaccurate idiom.

Actually, that's not correct. "Môn đăng hộ đối" is a misspelled word; the correct spelling should be "môn đương hộ đối" (门当户对). In other words, the word "đương" was misspelled as "đăng". "Đương " (当) means "suitable " or "matching," not " đăng " (灯: lamp).

In Chinese, " duo duang" (对当) means equivalent or equal, while "men hu " (门户) is a ideographic writing style, as expressed in the phrase: " Song fen vy men, dan fen vy hu " (Double door is the gate, single door is the house). "Men hu" has four main meanings: the entrance to a house; faction or sect; family or family status. Here, it's important to understand that this idiom has two parts: "men duang" and "hu dui".

A gatehouse (门当) is a pair of stone pillars or drums, often placed on either side of the gate of ancient buildings, or facing each other at the entrance of traditional Chinese buildings. In architecture, they are part of the "gatestones" (men dom shi), also known as gate pillars, gate bases, or ancient stone pillars. Gatehouses are often used to decorate gates and courtyards, marking the rank and status of the owner. For officials, the houses of military officials have round gatehouses , while those of civil officials have square ones.

Door lintels (户对) are carved bricks or wooden pieces used to secure door frames; because they are all even numbers, they are called "door lintels." Door lintels are usually cylindrical or square, each about 30 cm long, placed parallel to the ground. Because they protrude from the eaves and resemble hairpins worn by women in the past, door lintels are often called "door pins" (door clips).

In ancient times, officials below the third rank had two pairs of bronze tripods in front of their houses, those of the third rank had four, those of the second rank had six, and those of the first rank had eight. Only the imperial palace had nine sets, known as the nine bronze tripods (九鼎).

"Mén dàng huò" means that the family backgrounds and financial circumstances of both the man and woman are comparable, making them a suitable match for marriage. A synonym for "Mén dàng huò" is "Wàng xing duì yǔ" (望衡对宇), an idiom originating from the "Mǎn shuǐ" section of the Shui Jing Zhu , meaning "people living very close to each other can see each other"; its opposite is "Qí dà fǎi yǒu " (齐大非偶), an idiom from the sixth year of Duke Huan's reign in Zuo Zhuan by Zuo Qiu Ming of the pre-Qin period, meaning that excessive wealth or power is incompatible; a marriage without "mén dàng huò" is unlikely to be happy.

The term "matching social status " originates from Wang Shifu's play " The Romance of the Western Chamber" during the Yuan Dynasty, probably written during the Yuan Zhen and Da De periods (1297-1307), depicting a love affair between Cui Yingying and Zhang Junrui that transcends social status and feudal etiquette.

In the second part of *The Romance of the West Chamber*, there is the phrase: " However, it is not a matter of matching household status " (虽然不是门当户对), but this only shows that the origin of this idiom refers to marriage; in reality, the phrase "matching household status " appeared earlier in Zhang Duan Yi's * Gui Er Ji * (1179-1248) of the Song Dynasty: " It is necessary to have a matter of matching household status " (要得门当户对).

Source: https://thanhnien.vn/lat-leo-chu-nghia-mon-dang-ho-doi-la-thanh-ngu-khong-chuan-xac-185240628215620589.htm