四分律比丘含注戒本 2.537

2.537

If in the open ground he kindles grass, wood, twigs, leaves, hemp, linen, cow dung, chaff, manure, or refuse, in all cases it is a prāyaścittika. If he places fire amidst grass and wood, down to refuse, it is also a prāyaścittika. If an object is half-burned and he throws it into the fire, or kindles charcoal, it is a duṣkṛta. If he does not say to the person before him, "Know this, watch this," it is also a duṣkṛta. There is no offence: if he says, "Know this, watch this"; if a sick person kindles it himself or instructs another to kindle it; if there are proper circumstances of time, such as tending a sick person by cooking gruel, porridge, soup, or rice; if it is in a kitchen or a bathhouse; or if it is for fumigating a bowl, boiling dye, lighting a lamp, or burning incense—in all such cases there is no offence.