“وَ” (wa)a joining word meaning “and.” It connects this word to what came before.Corpus grammarCONJ — prefixed conjunction wa (and).
“رَبَّ” (rabba)means “And your Lord” in this verse. It is a noun. a naming word. Here it is masculine, accusative.Corpus grammarN — accusative noun.
“كَ” (ka)an attached pronoun meaning “you” when speaking to one man.Corpus grammarPRON — second person masculine singular attached pronoun.