Saint Ambrose is accompanied here by Saint Luke, engaged in writing with good probability his only exegetical work of the New Testament, the Expositio Evangelii secundum Lucam, behind the direct dictation of Saint Luke, who is seated on his own symbol, the calf. Of great charm, the composition, whose chromatic background stands on a vivid contrast between the bright blue and the ivory white of the fabrics of the dress of Saint Luke, proposes the two protagonists on the swollen and soft clouds between which angels plunge. The calf on which Luca rests highlights, as usual, the contours of a tender and close humanity, the one widely bestowed by Correggio to the animals that make up his lifework.