柬埔寨高棉人的 Pchum Ben (華僑稱之亡魂節)

Pchum Ben Khmer: ("Ancestors' Day") is a Cambodian religious festival, culminating in celebrations on the 15th day of the tenth month in the Khmer Calendar—Sept.

The day is a time when many Cambodians pay their respects to deceased relatives. Monks chant Pali overnight (continuously, without sleeping) in prelude to the gates of hell opening, an event that is presumed to occur once a year. During the period of the gates of hell being opened, ghosts of the dead are presumed to be especially active, and thus food-offerings are made to benefit them, some of these ghosts having the opportunity to end their period of purgation, whereas others are imagined to leave hell temporarily, to then return to endure more suffering; without much explanation, relatives who are not in hell (who are in heaven or otherwise reincarnated) are also generally imagined to benefit from the ceremonies.

In temples the offering of food itself is made from the laypeople to the (living) Buddhist monks, thus generating "merit" that indirectly benefits the dead; however, in many temples, this is either accompanied by or superseded by food offerings that are imagined to directly transfer from the living to the dead, such as rice-balls thrown through the air, or rice thrown into an empty field—the popular (if unorthodox) assumption that mortals can "feed" ghosts with physical food.

Link related to the photo of Pchum Ben, Cambodia: Pchum Ben - Search according to Google:

Pchum Ben is considered unique to Cambodia, however, there are merit-transference ceremonies that can be closely compared to it in Sri Lanka (i.e., benefitting the ghosts of the dead), and, in its broad outlines, it even resembles the Taiwanese Ghost Festival.