律戒本疏 1.100

1.100

四十七乃至二夜軍中往觀軍發行乃至軍陣合戰犯墮　亦遮習戰也。得二夜不得觀。而六群因觀。觀見者犯墮。欲觀不見犯突。有緣自行見無犯也。

Forty-seven: Up to two nights in an army, going to watch the army setting forth, or the army arrays clashing in battle, commits an offense of pāyattika. This also forbids [watching] military exercises. Although permitted two nights, one is not permitted to watch. Yet the group of six took the opportunity to watch. One who watches and sees it commits an offense of pāyattika. If one wishes to watch but does not see, one incurs a duṣkṛta. If one has an occasion and while walking on one's own sees it, there is no offense.