首楞嚴義疏注經 8.346

8.346

火際者，餓鬼所居處也，水輪向下至火輪際，近地獄也。受氣猛火者，由業力故，受猛火氣以為身也，故常被燒節節火起。水能害己者，苦於無水也，苟遇成火而燒其身，故云害己。

The border of fire is the dwelling place of hungry ghosts; from the water wheel downward to the boundary of the fire wheel, it is near the hells. 'Receiving a body of fierce fire' means that due to karmic power, one receives the fire's fiery breath to form a body, and thus is constantly burned, with fire blazing from joint to joint. 'Water can harm oneself' means suffering from the lack of water; if they encounter it, it turns to fire and burns their bodies, which is why it says 'harms oneself'.