Medieval European writers quoted the Qur’an itself to argue Christian doctrine at Muslims

Evidence

It is interesting to compare some Franciscan writers who also knew Syria. Fra Fidenzio, Tripoli’s (presumed) younger contemporary, used the same method as he, with a different bias; his chief interest was the Trinitarian controversy. He made use of the passage in stirah 11 which Tripoli gave at greater length. His translation is accurate, but elliptical; his omissions do not pervert the true sense of the text. He used great concision. — Norman Daniel, Islam and the West, 947

Categorization

• SEED: Article angle: how converting opponents by quoting their own scripture back at them worked across the Christian-Islamic frontier — a forgotten rhetorical technique of ‘scriptural jiu-jitsu.’