The altarpiece shows the Holy Trinity with Mary Magdalene, St John the Baptist and Tobias and the Angel.
The Holy Trinity appears as a vision between the penitent saints Magdalene and John in a bleak desert landscape. The Baptist is inviting the observer to worship the Trinity, and Mary Magdalene is turning to face it full of emotion.
The Holy Trinity was originally commissioned by the Arte dei Medici e degli Speziali (guild of the Doctors and Pharmacists) for the church of Santa Elisabetta delle Convertite in Florence, a church/monastery housing former prostitutes or fallen women, who had converted from the licentious life to one of honesty, and whose patron saint was Mary Magdalene.
The picture shows the Trinity (Jesus Crucified, God and the Holy Spirit's Dove) within an almond with seraphim. In the background is a blue sky within two rocky spurs, in front of which are Mary Magdalene, taken in an intense praying posture, and St. John the Baptist, patron saint of Florence, who, as usual in the pictures of the period, is pointing to the center of the composition. The exhausted figure of the penitent, a late work of Donatello's, had a decisive influence on Botticelli's Magdalene.