“فَ” (fa)This word resumes the flow after a pause or change in thought.Corpus grammarREM — prefixed rem particle.
“كَذَّبُ” (kadhkabu)means “So they denied them” in this verse. It is a verb. an action or state word. Here it is perfect verb, verb pattern two, third person — masculine — plural.Corpus grammarV — third person masculine plural perfect verb.
“و” (w)an attached pronoun meaning “they” or “them.”Corpus grammarPRON — third person masculine plural subject pronoun.
“هُمَا” (humā)an attached pronoun meaning “they two.”Corpus grammarPRON — third person dual attached pronoun.