In the ninth year, he ascended west to the Kunlun Mountains A mythical and sacred mountain range in the west, believed in Taoist tradition to be the residence of immortals and the site of Laozi's final departure from the human realm.; the total span of his time recorded was nine hundred and ninety-six years.

According to the Supplement to the Record of Diverse Matters by Li Shi original: "Li Shi Xu Bowuzhi." Li Shi was a Southern Song scholar who expanded upon earlier "encyclopedias of wonders.": In the third year of the Wude era 620 CE of Emperor Gaozu of Tang, a man from Jinzhou named Ji Shanxing was at Yangjiao Mountain Sheep's Horn Mountain when he saw an elderly man dressed in white. The old man called out to Shanxing, saying: "Tell the Tang Emperor for me: I am Lord Lao original: "Lao Jun," the deified title for Laozi., and I am your ancestor."

In response, Emperor Gaozu established a temple in his honor. Later, Emperor Gaozong The third Tang emperor, r. 649–683 CE. bestowed upon him the honorific title Mysterious Primordial Emperor Xuanyuan Huangdi: A title that officially elevated Laozi to the status of a divine imperial forefather of the Tang dynasty.. Emperor Minghuang Also known as Emperor Xuanzong, r. 712–756 CE. personally wrote a commentary on the Classic of the Way and Virtue The Tao Te Ching.. He decreed that scholars throughout the empire establish temples for the Mysterious Primordial Emperor in the two capitals Chang'an and Luoyang. and in various provinces. In the capital, the temple was named the Palace of the Mysterious Primordial; in the various provinces, they were called Palaces of the Purple Ultimate. Shortly after, the temple in the Western Capital Chang'an was renamed the Palace of Supreme Purity and the temple in the Eastern Capital Luoyang was renamed the Palace of the Great Subtle. Students were appointed to serve at all these locations.

The Honorific Title says:

Great Holy Ancestor, High Sovereign of the Great Way, Golden Portal, Mysterious Primordial Emperor of Heaven

The Collected Important Documents of the Song Dynasty original: "Song Guochao Huiyao." A historical record of the Song government's administrative and ceremonial activities. states: On the eleventh day of the eighth month in the sixth year of the Taiping Xiangfu era 1013 CE. This likely refers to the "Dazhong Xiangfu" era of Emperor Zhenzong. of Emperor Zhenzong of Song, it was decreed that we respectfully offer [the title]: