We know that the bhikshus had to support each other mutually in this work.
The bhikshus after having begged their food, likewise went back to the bamboo grove.
Thus Buddha, for the bhikshus' sake, explained the law in various ways.
When you have cut down both the forest (of lust) and its undergrowth, then, bhikshus, you will be rid of the forest and free!
He seems to say that it is right for the laity to make an offering of their bodies by burning but not for bhikshus.