فَسَوْفَ يَكُونُ لِزَاماً
(So the torment will be yours forever.) So your denial will remain with you forever, i.e., it will lead to your punishment, doom and destruction in this world and the Hereafter. This also refers to the day of Badr, as it was interpreted by `Abdullah bin Mas`ud, Ubayy bin Ka`b, Muhammad bin Ka`b Al-Qurazi, Mujahid, Ad-Dahhak, Qatadah, As-Suddi and others.