The group called the Altare del Santo composed altogether of twenty-nine pieces of sculpture. Among them, four bas-reliefs in bronze with the miracles of St Anthony (Miracle of the Ass, Miracle of the New-born Child, Miracle of the Repentant Son, Miracle of the Avaricious Man's Heart).

In the Miracles series Donatello adopted flattened relief on a roughened surface which served to break up the light and diffuse it, thus achieving a luminous atmosphere in which the incorporeal images appear to float. Never until now had architecture played such a prominent part in narrative relief scenes. In the Miracles it is the rhythm of the architecture that unites the jostling crowd and is felt to be the chief protagonist.

After he had died, the heart of a miser was found in the chest in which he hoarded his money while he was alive. This event is taking place on the left edge of the relief Miracle of the Avaricious Man's Heart, while St Anthony is in the process of opening the corpse's rib-cage.