Nāradaparivrājaka Upaniṣad 4.16

4.16

abhayaṃ sarvabhūtebhyo dattvā carati yo muniḥ |
na tasya sarvabhūtebhyo bhayamutpadyate kvacit ||

The great ones do not give up their self-restraint like the sun. When the muni takes, like a cow, the food with the mouth only (without the use of the hand), he becomes of equal vision to all beings. Then he becomes fit for salvation. He may, for alms, go from a forbidden house to a non-forbidden one. He should go (for alms) to a house where the door is ajar, but not to a house where it is closed. The muni who has a dusty body, an uninhabited house or the foot of a tree as his abode, without anything dear or not dear to him, sleeping where the sun sets, without any fire-warship, without any settled place and with patience and the organs under control, should live without any desire in any place obtained. He who after going to the forest dwells with jñāna as the sacrifice and the organs under his mastery and awaits his time (of death), is fit to be of the nature of Brahman. A muni who goes about with no cause for instilling fear into all beings need never have any fear from them. One without any abhimāna (identification with body) or egoism or dualities or doubt, never is angry, never hates, never lies through the vocal organ. That person who, having visited all sacred places, does not do any injury to any living creature and gets alms at the proper time, is fit to be of the nature of Brahman. He should not associate with a forester or householder. He should conduct himself in such manner as not to be known to others. He should not be glad of anything.