Surah 9. Al-Tawba, Ayah 20

See surah {2}, note [203], and surah {4}, note [124].

Here is a good description of Jihad. It may require fighting in Allah's cause, its a form of self-sacrifice. But its essence consists in (1) a true and sincere Faith, which so fixes its gaze on Allah, that all selfish or worldly motives seem paltry and fade away, and (2) an earnest and ceaseless activity, involving the sacrifice (if need be) of life, person, or property, in the service of Allah. Mere brutal fighting is opposed to the whole spirit of Jihad, while the sincere scholar's pen or preacher's voice or wealthy man's contributions may be the most valuable forms of Jihad.