Christian friars seeking martyrdom openly insulted Muhammad before Muslim rulers

Evidence

The Muslims took the friars to the “king” of Seville, whom the friars urged to convert, saying “many bad things about Muhammad and his damnable law.” The king had them imprisoned in a tower, from which they continued to preach, “damning Muhammad and his followers to eternal punishment.” (The chronicles do not say in which language the friars preached to the Saracens.) — John V. Tolan, Saracens, 1103

Categorization

• QUESTION: The chronicles don’t say what language the friars preached in — they were European Franciscans preaching to Arabic-speaking Saracens in Muslim Spain and Morocco. Worth chasing: did medieval missionary friars learn Arabic? How did they communicate?