Just this watery mass again. So it's creation undoing itself in some of the descriptions, as opposed to just heavy rain.

又变成了一个大水球,这里是自我毁灭，而不是毁于倾盆大雨。

耶鲁公开课 - 旧约导论课程节选

Sometimes the flood seems to be the result of very heavy rain, but in other descriptions it seems to be a real cosmic upheaval.

有人说，大洪水是大雨导致的，还有人说，是因为宇宙变动引起的。

耶鲁公开课 - 旧约导论课程节选