﴿ نَذِيرًۭا لِّلْبَشَرِ ﴾

“a warning to mortal man –”

(As a warning unto men) it is also said this means: Muhammad (pbuh) is a warner unto mankind. This leads us to the beginning of the surah and Allah's saying (Arise and warn), this latter part being mentioned last when it is the first part of the sequence,