The Dendrite Discipline
David belongs to the rare ascetic current of the dendrites, whose name derives from the Greek word for "tree." Where the stylites mounted pillars to wage their struggle apart from the world, the dendrites took up their abode among the branches of a tree. The OCA synaxarion records that David, "inspired by the example of the holy stylites," lived in an almond tree in constant prayer, keeping strict fast and enduring heat and cold, and that he remained there for three years until an angel told him to come down.
By the account preserved in his life, David attained a state of dispassion so complete that he was "like an angel in the flesh," and was able to take hot coals into his hands without harm. Such details are transmitted as part of the saint's vita and tradition rather than as documented history.
Wonderworking and Counsel
Saint David received from God the gift of wonderworking, through which he healed many from sickness, and he gave spiritual counsel to all who came to him. His reputation for wise counsel is said to have drawn numerous seekers even before his withdrawal into the almond tree.
According to the wider tradition recorded of him, David later left his solitude to travel to Constantinople on behalf of his city, petitioning the Emperor Justinian I for the protection of Thessaloniki. By this account he reposed in the year 540 while still traveling, before completing his return.
Veneration
Saint David is venerated as a patron of Thessaloniki and is commemorated in both the Eastern Orthodox and Roman Catholic Churches. His principal feast falls on June 26; in the Greek Orthodox Church a commemoration on September 16 marks the translation of his relics.
A relief icon of the saint, dated to the thirteenth or fourteenth century, is preserved in the Museum of Byzantine Culture in Thessaloniki, witnessing to his enduring place in the devotion and religious art of the city.