The quote, from Scaramucci's interview with CNN: "If you want to talk about [Reince Priebus], we have had odds. We have had differences. When I said we were brothers from the podium, that's because we're rough on each other. Some brothers are like Cain and Abel. Other brothers can fight with each other and get along. I don't know if this is reparable or not, that will be up to the president."
About the reference: Those who have forgotten their Genesis should note that Cain killed Abel.