法華論疏 3.322

3.322

報佛既常，如前所釋，當知報佛之土亦常，以常故不可燒也。問：既是常土，云何得有諸天擊鼓及散華等耶？答：於常土無障礙用故，得有斯事也。

Since the reward Buddha is permanent, as explained previously, one should know that the land of the reward Buddha is also permanent; and because it is permanent, it cannot be burned. Question: Since it is a permanent land, how can there be the devas beating drums, scattering flowers, and the like? Answer: Because within the permanent land there is unobstructed function, there can be such occurrences.