I'm not sure if I understand this quote fully. I have some idea, but not sure.
He's talking about his son not being Arab, right?
yes. His father is a right winger in denial about his son's evil.. So he is saying of course his son will be pro israel, "what is he, an arab?"
that's probably one thing his father tells himself "at least my son's not an arab!" "my son wouldn't do that, he's not an arab" e.t.c.
And please explain the significance of mopping. Are Arabs in Israel typically janitors?
Even in israel, the lower paid jobs e.g. Cleaners(including those that mops floors),, Jews tend not to go for that kind of job.