The function of inverted willow board in geomantic omen

1, ward off evil spirits. As the saying goes, ghosts are afraid of willow. The source is that there are two gods who catch ghosts. After catching the ghost that harms the world, tie it with willow branches and feed it to the tiger. 2, Liu homophonic is "stay", meaning to keep, planted in front of the door, in order to keep family members and patients from following ghosts. And don't let the money slip away.