Arise and warn 2.
2. This means warn every person, in every period and in every way, because your Prophethood is common to everyone, for every period and for every place. From this, we learn that Allah Almighty created the Holy Prophet fully developed as all-knowing and omniscient because up to that time the Holy Qur'an had not mentioned Hell, etc. but he said that to warn them.
If the Holy Prophet صلى الله عليه وآله وسلمwere not aware of these things, then how would he warn them? Therefore, the Holy Prophet صلى الله عليه وآله وسلم had said I am an unconcealed warner, i.e. I see the danger, and then warn.