وَشَاهِدٍۢ وَمَشْهُودٍۢ
Sentence structure
وَشَاهِدٍ is another coordinated genitive oath noun. وَمَشْهُودٍ is coordinated with it and is likewise genitive.
Ayah summary
An oath is sworn by the witness and what is witnessed.
وَشَاهِدٍۢ — And (the) witness
Grammar: وَ coordinates; شَاهِدٍ is an indefinite genitive active participle used as a noun in the oath series.
وَمَشْهُودٍۢ — and what is witnessed
Grammar: وَ coordinates; مَشْهُودٍ is an indefinite genitive passive participle coordinated with شَاهِدٍ.