وَعِشْرِينَ رَجُلًا
Translation: And twenty men (after the preposition in the full sentence).
وَ: conjunction.
عِشْرِينَ: coordinated with «مُسْلِمِينَ», now genitive with yāʾ through the shared prepositional construction.
رَجُلًا: accusative tamyīz, even though its number is genitive.
Contrast: The written form «عِشْرِينَ» was accusative in the preceding source sentence and is genitive here.