فَسَاقَتْهُمْ إِلَيْكُمْ أُمْنِيَّةٌ أَشْرَاءُ
An arrogant wish is depicted as driving the opposing force toward its object.
Sāqat is third-person feminine singular past tense, -hum its object, and umniyyatun its delayed subject. Since a wish cannot literally drive an army, the grammar itself produces personification. Overconfidence becomes the cause of the trial the speaker describes.