Muslims in Jerusalem prepare to defend themselves against a new attack. But precisely in order to attack, the Crusaders need new siege devices, and therefore wood: they will have to get it in the only place handy, that is the forest that has been enchanted by Wizard Ismen, though they obviously don't know about this.
Ma in questo mezzo il pio Signor non vuole
Che la forte città in van si batta,
Se non è prima la sua maggior mole
Et alcuna de l'altre ancor rifatta.
E i fabri al bosco invia, che porger sole
Ad uso tal pronta materia ed atta.
Questi a l'oscura selva andar con l'alba,
Quando l'oscuro ciel primier s'inalba.
Meanwhile, the pious Lord (*) does not mean to attack the strong city in vain, unless the bigger device and some more are rebuilt. So, he sends the carpenters to that wood that can provide them with suitable materials. They went to the dark forest (**) at dawn, when the dark sky just begins to get clearer.
(*) Godfrey of Bouillon, the head of the Crusaders. He is called "pious" -- meaning "righteous, devoted to duty, and God-fearing" in Latin -- after Aeneas, who in the Middle Ages and the Renaissance was considered the model leader par excellence, a providential or even Christian leader ante litteram.
(**) Here the reference to Dante's selva oscura is expressly pointed out. The last line seems to add solemnity and a feeling of sacred expectation to the episode by hinting at John 20: 1.