梵網經菩薩戒本疏 5.82

5.82

Seventh, permissible and impermissible circumstances: In the text, regarding mountains and wildernesses, setting fire from the fourth month to the ninth month constitutes an offense; at other times it does not constitute an offense, which is the same as the precept in the Vinaya against kindling fires in the open, and so forth. Regarding the burning of houses and the like, all constitute an offense. The Mahīśāsaka Vinaya states that burning wildernesses does not constitute a major offense; this appears to correspond to that verification.