Quran (9:41) - "Go forth, light-armed and heavy-armed, and strive with your wealth and your lives in the way of Allah! That is best for you if ye but knew." See also the verse that follows (9:42) - "If there had been immediate gain (in sight), and the journey easy, they would (all) without doubt have followed thee, but the distance was long, (and weighed) on them" This contradicts the myth that Muslims are to fight only in self-defense, since the wording implies that battle will be waged a long distance from home (in another country and on Christian soil, in this case, according to the historians).