At 3rd level, a paladin gains the Sacred Oath feature. The Oath of Healing is another option paladins can choose.

Oath of Healing

The Oath of Healing holds a paladin to a path of remedy and purity, sworn to rid the world of disease and other ills. In joining martial technique with medicine and remedy, these paladins are battlefield doctors and miracle workers alike. Whether called upon suddenly to quell an epidemic or in perpetual service in the endless war against disease, they are often as grim in manner as the inevitable death they choose to fight against. Called plague knights and hospitaliers, such paladins can be counted on to heal ailment and smite impurity, healing the world one patient - or disease - at a time.

Tenets of Healing Often sworn as the paladin stands before a cleansing fire, it is traditional for one to write the tenets of the Oath of Healing upon parchment and then hold it out to burn in the flame. Treat the Afflicted. Disease is no respector of persons, and in your role as healer, neither are you. Make your remedies and ministrations free to all who are in need. Cleanse Impurity. You possess understanding of vectors and illness, so it is your charge to stop diseases at the source when you find it. Mourn in Tragedy. When a patient's war on death is finally at an end, join in sorrow with the others that are left behind.

Oath Spells You gain oath spells at the paladin levels listed. Oath of Healing Spells Paladin Level Spells 3rd false life, sleep 5th lesser restoration, protection from poison 9th feign death, revivify 13th aura of life, fire shield 17th greater restoration, mass cure wounds