आलोड्य सर्वशास्त्राणि विचार्य च पुनःपुनः |
इदमेकं सुनिष्पन्नं वैद्यो नारायणो हरिः || ||

'Phalashruti' of Vishnu sahasranaama(Thousan names of Vishnu':

Having carefully scrutinized all the scriptures and having reflected
upon them well again and again this truth has clearly emerged that
Vishhnu, the Lord Hari living in the ocean is THE doctor (who removes all ills).