Tommaso Portinari knelt on the left leaf before the open door to the shed. He is represented by Saint Thomas with a spear in his hand, which put his foot on the floor of his cloak.
The young sons of Portinari Antonio and Pigello are kneeling behind him; the first one is Saint Anthony, who can be recognized by the bell, its attribute. Probably, the lack of space prevented the image of the younger sons of the donor.
Related Paintings 
Christmas (Altar of Portinari). Right wing by Hugo Gus 
Navidad (Altar Portinari).Ala izquierda – Hugo Gus 
Noël (autel de Portinari). Aile gauche – Hugo Gus 
The Adoration of the Shepherds (Altar of Portinari) by Hugo van der Gus 
Christmas (Altar of Portinari). In the closed state by Hugo Gus 
Navidad (Altar Portinari).Ala derecha – Hugo Gus 
Adoración de los pastores (Altar de Portinari) – Hugo van der Goes 
Navidad (Altar Portinari). En estado cerrado – Hugo Gus
Christmas (Altar of Portinari). Right wing by Hugo Gus Navidad (Altar Portinari).Ala izquierda – Hugo Gus Noël (autel de Portinari). Aile gauche – Hugo Gus The Adoration of the Shepherds (Altar of Portinari) by Hugo van der Gus Christmas (Altar of Portinari). In the closed state by Hugo Gus Navidad (Altar Portinari).Ala derecha – Hugo Gus Adoración de los pastores (Altar de Portinari) – Hugo van der Goes Navidad (Altar Portinari). En estado cerrado – Hugo Gus