they strongly swear by god that they would march to fight if you were to order them to. tell them you do not need to swear fighting for the cause of god is a virtuous deed and god is well aware of what you do.
وأقسموا بالله جهد أيمانهم لئن أمرتهم ليخرجن قل لا تقسموا طاعة معروفة إن الله خبير بما تعملون