The word(s) "backing" appears 2 time(s) in 2 verse(s) in Quran in Muhammad Habib Shakir translation.

(1) Yet you it is who slay your people and turn a party from among you out of their homes, backing each other up against them unlawfully and exceeding the limits; and if they should come to you, as captives you would ransom them-- while their very turning out was unlawful for you. Do you then believe in a part of the Book and disbelieve in the other? What then is the re ward of such among you as do this but disgrace in the life of this world, and on the day of resurrection they shall be sent back to the most grievous chastisement, and Allah is not at all heedless of what you do.

(2) But (now) when the truth has come to them from Us, they say: Why is he not given the like of what was given to Musa? What! did they not disbelieve in what Musa was given before? They say: Two magicians backing up each other; and they say: Surely we are unbelievers in all.