dingsang
Placing the stone base beneath a pillar. 'Sang' is the stone that supports the pillar's foot.
Dingsang is the essential first step of laying a stable foundation for a pillar when building a house. The stone placed under the pillar's foot (called a 'sang') must be set level and secure, as it will bear the weight of the entire structure. Traditionally, this step is performed on an auspicious day, as it is believed that the stability of the stone base directly affects the building's longevity and the peace of its inhabitants.