Ravana receiving Mayashakti from Lord Shiva is part of Tamil
folklore and is found in the Tamil Ramayana. Ravana once did intense penance
and pleased Shiva. As a boon, the demon king asked Shiva to give him Goddess
Parvati. Shiva agreed to the wish of his devotee.
When Ravana was carrying Goddess Parvati to Lanka, Lord
Vishnu took the form of a sage and stood near a garden with upside-down trees.
The roots of the trees were in the air.
Ravana stopped to inquire about the strange tree. The sage
wanted to know about the beautiful woman. When he heard, it was Goddess
Parvati; the sage laughed and told Ravana that Shiva cheated him by giving him
Mayashakti and not the real one.
Ravana believed the sage and he left the false Parvati with
sage and went to procure materials needed to perform intense austerities to get
the real Parvati.
As soon as Ravana left, Vishnu went away with Goddess
Parvati to Kailash.
Ravana soon returned to look for the Sage and the false
Parvati but both were missing.
Ravana searched for them everywhere. Shiva made Goddess
Parvati invisible using the sacred ash.
When his search turned futile, Ravana again performed
intense Tapas and this time Shiva gave him Mayashakti. Ravana believed it to be
the real Parvati and left for Lanka.
Once again, he stopped near the sacred grove with upside
tree. This time the Sage told the demon king that he received the real boon and
real Parvati.
Ravana was content and he went to Lanka with Mayashakti not
knowing that he was deceived by Shiva and Vishnu.