Zenobius
Zenobius was a bishop of Florence who lived between 337 and 417 CE. He became the city's chief patron saint. Three different miracles are credited to him in which he raises the dead. The blood on the pavement shown on the Fitzwilliam panel suggest that we are here witnessing the miraculous revival of a child knocked down by an ox cart on the streets of Florence.
The moment that Domenico has chosen is that just before the miracle has been worked, while the saint quietly prays, and a group of passers-by look on. The focus of our attention here, however, is the child's mother, who leans over her son, her face a mask of grief and horror.