The Tribute Money is the most famous and important fresco in Brancacci chapel, and the true key of the pictorial cycle. Christ shows St. Peter how to get the coin to pay the taxes: the man who commissioned the painting, Felice Brancacci, had become wealthy as a tax collector, and his intention was to illustrate the passage of the Gospel where Christ himself shows that he must pay what's due ("Give to Caesar what is Caesar's, and to God what is God's").
In a single landscape that has been reduced to the bare essentials and is therefore of immediate effect, three different and subsequent moments are depicted: in the center, Christ tells Peter that the coin lies in the bowels of a fish; at the sides, Peter goes fishing, and then goes to the tax office to pay the tribute to the tax collector. As you can see, Masaccio concentrates all the painting's tension in the group of figures and their eloquent gestures and solemn expressions, enhancing their monumentality.