Before an emperor was born in history, his mother dreamed that the sun was swallowed in her mouth.

Zhao Guangyi, Song Taizong, this man and Zhao Kuangyin are brothers of a female compatriot. In order to show the legitimacy of the succession, he claimed that his mother was pregnant because she dreamed that a god held the sun in her hand and put it in her stomach. When I was born, the red light went straight through the delivery room and condensed in the sky like a fire, and all the neighboring streets smelled strange fragrance. It's almost exactly what his brother advertised.

Tuoba Xuan, Emperor Daowu of the Northern Wei Dynasty, dreamed that the sun entered the room. "Seeing the light and dying, I suddenly realized something." Pregnant. During delivery, the delivery room is well lit at night.

Yuan Ke, Emperor Xuanwu, in the Northern Wei Dynasty, her mother Linda Gao was chased by the sun and hid under the bed. The sun immediately turned into a dragon and wrapped around her several times. When she woke up, she was pregnant.

I don't know which one is-very similar to what you described, right?