O believers! Do not take oaths to deceive each other, lest your foot slip after being firmly fixed upon guidance; and you will taste the evil consequences for hindering others from the Way of Allah and you will suffer a tremendous punishment.
Meaning:-
consequences: result or effect of something.
Hindering: to prevent from doing, to block or put something in the way of, stop someone.
Tremendous: really awful and terrible, extraordinarily great in size.