'Neighbour' in the Bible

If a man doth sin against his neighbour, and he hath lifted up on him an oath to cause him to swear, and the oath hath come in before Thine altar in this house --

and the sons of Ammon stand up, and Moab, against the inhabitants of mount Seir, to devote and to destroy, and at their finishing with the inhabitants of Seir, they helped, a man against his neighbour, to destroy.