Thus have I heard:
One time, the Budha was staying at Anaathapindidas Ashrama in Jetavana of Shraavastii.
At that time, Bhagavaan said to the bhikshus, “If an aranyaka bhikshu (forest-dwelling) dwells in solitude, away from the community, he should constantly maintain reverence and cultivate a mind of joyful diligence.
If, however, a aranyaka bhikshu who dwells in solitude lacks reverence and fails to develop joyful diligence, then even if he were amid the assembly, others will criticise him, saying, ‘This aranyaka bhikshu does not know the way of forest-dwelling – he lacks reverence and joyful diligence!’
“Furthermore, Bhikshus, a aranyaka bhikshu dwelling in solitude, away from the community, should always be diligent and avoid laziness and negligence. He should fully understand the essence of all dharmas. But if an aranyaka bhikshu in solitude is lazy and engages in unwholesome actions, then even if he were amid the assembly, others will criticise him, saying, ‘This aranyaka bhikshu is lazy and lacks diligence.’
Therefore, bhikshus, an aranyaka bhikshu dwelling in solitude apart from the community should always cultivate humility and joyful diligence, avoid laziness and disrespect, practice diligence, and remain steadfast in his resolve. He should fully develop all wholesome qualities. Thus, bhikshus, you should train yourselves.”
When the bhikshus heard what the Budha said, they followed it with joy.