This painting, of medium size, occupies an unusual place in the middle of the Te Deum, which it illustrates. Men of the Middle Ages saw a close relationship hetween the baptism of Saint Augustine and the origins of this magnificent rich song whose verses in praise of God alternate like a noble dialogue.
According to Jacopo da Voragine's The Golden Legend, on Easter day Augustine received baptism with his son, Adeodatus, born to him while he was still a pagan philosopher, and his friend Alypius, converted like Augustine by the words of Saint Ambrose.
After public confession and baptism Saint Ambrose cried "Te Deum Laudamus, " to which Augustine replied "Te Dominum confitemur"; their alternate words of praise continued on to make up the whole hymn.
The Limbourgs represented the scene in a hexagonal baptistery with red vaults. Immersed to his waist in the baptismal font, Augustine wears a miter that symbolizes his future office of bishop of Hippo in Africa.
Dressed in priestly vestments and wearing the miter of the archhishop of Milan, Saint Ambrose pours the haptismal water over Augustine's head. Various figures complete the scene, including one wearing a pointed turban, one contemplating the baptism, and others commenting on it.
Inside the initial letter, from which colored foliage spreads, we see painted with a fine, light brush, a praying figure, perhaps meant to represent Saint Augustine.

small image (25KB) --- large image (232KB) --- Upper center detail (large) (243KB) --- Saints Ambrose and Augustine (large) (262KB)