Zacchaeus
A common reflection during Lent is on the story of Zacchaeus as recounted in Luke 19:1-10.
In this way the Lenten journey should begin with a recognition of sinfulness, just as Zacchaeus recognized his sins. He promised to make restitution by giving half of his wealth to the poor and by paying to those he had falsely accused four times as much as they had lost. In this, he went beyond the requirements of the Law (Ex. 22:3-12). Just as Zacchaeus "sought to see who Jesus was" (Luke 19:3), that same desire and effort to see Jesus starts the movement through Lent towards Easter. It is the first movement of salvation.
The painting is a traditional icon of the scene in which Zacchaeus is so determined to see Christ that he climbs a tree in order to do so. Notice how the other onlookers and even the mountains and the tree bow before their Creator.