The Gemara (Nedarim 39B) says that one who visits a sick person takes away one-sixtieth of his sickness. Sefer Imrei Noam asks what the purpose of this is. If the sickness is still there, what difference does it make if one-sixtieth of it is removed?
He answers by quoting Sefarim Hakedoshim (see Shaar Hagilgulim, Hakdamah 2) that say that when a person does a mitzvah, the neshama of a tzadik who excelled at that mitzvah accompanies him. The Sefarim (Emek Hamelech, Hakdamah Shlishis, Perek 4) relate a story of a Rov who performed a great mitzvah of tzedakah and redeeming a captive. As a result, he was accompanied by the soul of Rav Pinchos ben Yair, who was connected to this mitzvah (see Chulin 7A).
The first time we read about the mitzvah of bikur cholim, the one visiting the sick was the holy Shechinah itself (Bereishis 18:1), when it visited Avrohom. Therefore, when one fulfills this mitzvah, the Shechinah accompanies him when he goes to visit the sick. This explains the words of Chazal (Nedarim 40A) that “the Shechinah is by the head of a sick person.” And this will certainly ultimately lead to a complete recovery, as Hashem heals and sustains the sick (Tehillim 41:4).
