And Abu Darda (may Allah be pleased with him) said that you fight (in battle) because of your (righteous) deeds, and the statement of Allah the Exalted (in Surah As-Saff) «يا أيها الذين آمنوا لم تقولون ما لا تفعلون * كبر مقتا عند الله أن تقولوا