Sabbatai Zevi visited him in hopes of curing him from an illness that he had contracted. (Gershom Scholem later believed that Sabbatai Zevi suffered from a psychological condition he identified as "manic-depressive psychosis", today normally called "bipolar disorder".) Instead of trying to aid him with his psychological sickness, Nathan of Gaza divulged to Sabbatai Zevi his prophetic vision.
Sabbatai Zevi sought medical attention for an illness, while Nathan of Gaza shared his prophetic visions.