SB 2.7.21
dhanvantaris ca bhagavan svayam eva kirtir
namna nrnam puru-rujam ruja asu hanti
yajñe ca bhagam amrtayur-avavarundha
ayusya-vedam anusasty avatirya loke
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Lord in His incarnation of Dhanvantari very quickly cures the diseases of the ever-diseased living entities simply by His fame personified, and only because of Him do the demigods achieve long lives. Thus the Personality of Godhead becomes ever glorified. He also exacted a share from the sacrifices, and it is he only who inaugurated the medical science or the knowledge of medicine in the universe.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
As stated in the beginning of the Srimad-Bhagavatam, everything emanates from the ultimate source of the Personality of Godhead; it is therefore understood in this verse that medical science or knowledge in medicine was also inaugurated by the Personality of Godhead in His incarnation Dhanvantari, and thus the knowledge is recorded in the Vedas. The Vedas are the source of all knowledge, and thus knowledge in medical science is also there for the perfect cure of the diseases of the living entity. The embodied living entity is diseased by the very construction of his body. The body is the symbol of diseases. The disease may differ from one variety to another, but disease must be there just as there is birth and death for everyone. So, by the grace of the Personality of Godhead, not only are diseases of the body and mind cured, but also the soul is relieved of the constant repetition of birth and death. The name of the Lord is also called bhavausadhi, or the source of curing the disease of material existence.