وَمَجْرُورًا إِذَا كَانَ قَبْلَهُ حَرْفُ جَرٍّ أَوْ مُضَافٌ، نَحْوُ: «بِكَمْ رَجُلًا مَرَرْتَ»، وَ«عَلَى كَمْ رَجُلٍ حَكَمْتَ».
Translation: Kam occupies a genitive position when preceded by a preposition or used as the genitive complement of a noun; examples include “By how many men did you pass?” and “Over how many men did you rule!”
In بِكَمْ, bi governs kam in the genitive position, while rajulan remains an accusative interrogative tamyīz. In عَلَى كَمْ, kam is similarly governed; declarative rajulin is a genitive tamyīz.