عَلِقْتُهَا عَرَضًا وَأَقْتُلُ قَوْمَهَا زَعْمًا لَعَمْرُ أَبِيكَ لَيْسَ بِمَزْعَمِ
I fell in love with her unexpectedly even while fighting her people; by your father’s life, this is no idle or unfounded claim.
ʿAliqtuhā ʿaraḍan means the attachment arose unexpectedly. Wa-aqtulu qawmahā juxtaposes private affection with the collective reality of tribal fighting.
La-ʿamru abīki is an oath formula. Laysa bi-mazʿam denies that this is merely a hollow assertion, playing on the related expression zaʿman.