In Mexico City of July 21 of 1787, the priest Br. D. Nicolas Calvo fell gravely ill from malignant dysentery, and because some of the tissue of the last intestine had separated, a sure and certain death was feared by the doctors attending him; but having sincerely implored to the Santissima Virgin, he regained his health perfectly, with much admiration from the doctors, so much for the brevity of his recovery, as for the circumstances of it. And in recognition of this benevolence he offers the Santissima Virgin this retablo, in memory of it.

From Pestilence and headcolds: encountering illness in colonial Mexico by Sherry Fields