Khenpo Sodargye
In the Mahāyāna-Sūtrālamkāra-Kārikā, there is a case-study of a demon king who took the illusory appearance of a monk. While a Dharma master was expounding the Dharma to the monastic assembly, this monk stood up and declared that he had already attained the state of Arhat.
The Dharma master then posed certain questions to this monk to ascertain his claim—for example: How does one enter meditative concentration? How are afflictions eradicated? The monk’s answers were in contradiction to the genuine Dharma. The Dharma master therefore told his disciples that this person was not an Arhat.
At that moment, the monk suddenly levitated in the air and displayed eighteen kinds of miracles. Seeing this, many disciples developed faith in him and began ridiculing the Dharma master, saying, “How can you fail to recognize such an extraordinary Arhat?”
Yet the master’s view and insight were extremely firm. No eloquence or miraculous powers displayed could shake his certainty, he continued to explain the authentic principles of the Buddha-Dharma. Finally, the demon king himself was convinced by the truth and revealed his true form.
(Note: Past masters or practitioners have also used this method to test beings who claimed to be certain holy beings or Bodhisattvas etc, whether in person, visions, dreams or by possession (through an oracle/medium)-- that is, by checking their understanding of Dharma.
