Translation:

19. "And thou didst a deed of thine which (thou knowest) thou didst and thou art an ungrateful (wretch)!"

Notes (Tafseer)

3148. Further, Pharaoh reminds Moses of his having slain the Egyptian, and taunts him: "You are not only a murderer: you are an ungrateful wretch" (using kafir again in a double sense) "to have killed one of the race that brought you up!"