Fabi ayyi aalaaa'i Rabbikumaa tukazzibaan
Word By Word:
Fabi ayyi: So which
alaa'i: (of the) favours
Rabbikuma: (of) your Lord
tukazzibaan: will ye both deny?
Translation:
Then which of the favors of your Lord will ye deny?
Ayah Tafseer:
And the Ayaah get's repeated to express the importance: Then which of the blessings of your Lord will you both deny.
Source: Yusuf Ali Translations