Hi. Actually I have listened to it . Sou Ya Sou is not an Arabic phrase! It is just said to suit the rhythm of the song I think. It seems a funny song . I liked it :)

Hello. Just as daisy previous stated, 'sou ya sou' is not a proper arabic phrase. You will find in many arabic songs the overuse of "filler" words and phrases to make the song catchy and flow well with the rhythm. p.s I really like the song :-)