لماwhen التقيتمyou met one another وقدand indeed كاfirst part of 'they were'
لما التقيتم وقد كا
نواremainder of 'they were' يحملونthey carry سلاحاweapons
نوا يحملون سلاحا
When you met, while they were
carrying weapons,
اثخنتهمyou grievously wounded them انتyou سباwith insults
اثخنتهم انت سبا
واثخنوكand they grievously wounded you جراحاwith wounds
واثخنوك جراحا
you battered them with insults,
and they battered you with wounds.