Donatello. David. c1425-1430. Bronze, height 5'2" Museo Nazionale del Bargello, Florence

 Many scholars have noted with interest the way a curl of Goliath's beard has found its way between two of David's sandal-clad toes. This slightly disturbing facet of the sculpture has various interpretations. One is that, as Donatello was openly homosexual, the beard-and-foot interaction was meant to convey his sexuality.

Another interpretation suggests that it was meant as commentary on "homosocial" values: in Florence during this period it was common for men to believe they could achieve true love only with other men. Perhaps Donatello was tactfully expressing, through David's foot and Goliath's beard, his own opinion on the subject.
 
David is described in the Bible as a perfect, beautiful youth. Donatello's rendering of the heroic shepherd boy captures this youthful beauty perfectly, if somewhat effeminately. The sculpture has provided critics and scholars throughout the centuries with fodder for analysis and conjecture.

Form:  This lifesize bronze sculpture stands in a contrapposto stance.  His musculature is that of a young boy, probably around the age of thirteen or so.  The hat he wears (described by Stokstad as jaunty) is anachronistic and possibly out of place even for a shepherd boy from Italy in the 15th century.  David stands atop the bearded and helmeted head of Goliath who he has just vanquished.

Iconography and Context:  According to Janson, "this is the first life sized free standing sculpture since antiquity."  The figures size and pose are almost direct references to the classical tradition of casting idealized athletic figures in bronze with the lost wax process as evinced by the Doryphoros and Riace Bronzes (although they would not have been familiar with the bronzes since they were discovered in the 1970's).  In this way, Donatello would have combined the Bible story of David and Goliath with the classical and humanistic concept of kalos.  In effect, he was uniting both a theological and neoplatonic/humanistic point of view.

The iconography also points towards a political point of view.  The Italian city states were constantly at war with each other.  For example, Florence thought of themselves as the "David" to Rome's Goliath.  In this case, David is standing atop Goliath's head who sports a helmet.  According to Janson's Art History, the "elaborate helmet of Goliath with visor and wings, (is) a unique and implausible feature that can only refer to the dukes of Milan, who had threatened Florence."  For Janson, the hat David sports is then a reference to peace.

You may find Donatello's David a little bit ridiculous looking in his sun hat and almost effeminate stance and you are in good company.  Irving Stone's the chapter entitled "The Giant" from the book The Agony and the Ecstasy excerpted in Liaisons (page 164) Michelangelo explains why he thinks Donatello's version of David is ridiculous.