"The punishment of those who wage war against Allah and His Messenger, and strive with might and main for mischief through the land is: execution, or crucifixion, or the cutting off of hands and feet from opposite sides, or exile from the land: that is their disgrace in this world, and a heavy punishment is theirs in the Hereafter;" - Quran 5:33 (read more)

"O Allah's Apostle! We asked you for mounts, but you took an oath that you would not give us any mounts; we think that you have forgotten your oath.' He said, 'It is Allah Who has given you mounts. By Allah, and Allah willing, if I take an oath and later find something else better than that. then I do what is better and expiate my oath.'" - Sahih Bukhari 7:67:427 (read more)

"...the Messenger of Allah (may Allah bless him and grant him peace) used to go out on military expeditions or send out an army at least every two months. The virtuous Companions continued upon the path of the Noble Prophet (may Allah bless him and grant him peace), for the Glorious Qur'an had brought up this generation with an education of Jihad. They had been bathed in Jihad and cleansed of engrossment in worldly matters, just as a wound is bathed in water." - Imam Abdullah Azzam