O Muhammad, admonish with this (The Qur’an), those who have the fear of being assembled before their Lord in such a condition that there will be no one to protect them or intercede on their behalf other than Him. It may be that, by this admonition, they may become righteous.
Meaning:-
Admonish: to caution, advise, or counsel against something
Intercede:to act or interpose in behalf of someone in difficulty or trouble, as bypleading or petition