Let them not grieve you read yuhzinka or yahzunka from 1st form hazanahu ‘he made him grieve’ an alternative expression to 4th form ahzanahu ‘he made him grieve’ those that vie with one another in unbelief succumbing to it promptly by supporting it namely the Meccans or the hypocrites in other words do not be concerned for their unbelief; they will not hurt God at all by their actions only hurting themselves. God desires not to assign them any portion any lot in the Hereafter that is in Paradise and that is why God forsook them; and theirs is a mighty chastisement in the Fire.