A kind of Labdhi (supernatural power);
that supernatural power, attained through the yoga (spiritual practices like Tapa, Dhyāna etc.), by dint of which the speech of such practitioner becomes as melodious and ecstatic as milk.
'khīrāsava' tti kṣīravanmadhuratvena śrotṛṇāṃ karṇamanaḥsnkhakaraṃ vacanamāśravanti- kṣaranti ye te kṣīrāśravāḥ.
(AupaVṛ Pa 53)