Xu Ri Shu (Void Solar Rat)

Xu is the fourth of the Seven Northern Xuanwu Constellations and is associated with the sun, taking the form of a spiritually awakened rat. 'Xu' signifies tombs and burial grounds; the Xu constellation lies near the winter solstice point, and ancient astronomers used its position to determine seasonal transitions. In Daoism, it is venerated as Lord Xu Ri Shu. Astrological tradition holds that the Xu constellation presides over matters of death, mourning, and lamentation; thus, folk worship of Lord Xu Ri Shu commonly focuses on averting disasters, relieving misfortune, and performing rites for the deceased. The Xu constellation’s designated day is considered inauspicious for opening businesses or holding weddings. Devotees revere Lord Xu Ri Shu as the sovereign guardian of the threshold between the human and underworld realms—approached with solemn respect, never with levity.