The first mural is a Tree of Jesse, which sums up the theme of Old Testament prophecy pointing to Christ. At the bottom was the Latin text (which has not survived) of Isaiah 11:1: Et egredietur virga radice Jesse et flos de radice ejus ascendit, "And there shall come forth a rod out of the stem of Jesse, and a branch shall grow out of his roots."
Above this inscription is a badly faded King David playing his harp, framed by a vine and flanked by praying figures. The vine frame directly above David is occupied by the Virgin holding the infant Christ. She is a beautiful figure, drawn by a highly skilled hand. She stands in a graceful S-shape and is clothed in a blue mantle with draped folds.