The red gate refers to the palace gate, which was painted red in ancient times, and it originated from "living with Wu Zhenren", "seeing the son of heaven under the red gate with a book on his sleeve", "driving into Shilu Garden to observe discipline" and "the sunshine in February is like water, and the red gate is silent".

The palace gate is the gate of the palace where the emperor and the prince live; Borrow the palace.

Example:

1, Tang Yuanzhen's poem "Shang Yang White-haired Man": "When the palace gate is closed, Shang Yang's flowers and plants grow moss."

2. The third scene of the drama "Mi Jian You Gong": "Wu Xiangnv took Gong E to see the young master and walked out of the palace gate in new clothes."

3, Qing Kong Ren Shang "Peach Blossom Fan Treasures": "The day before yesterday, the emperor left privately and his concubines fled. It is expected that Xiang Jun will also go out of the palace. "