﴿ مَآ أَنتَ إِلَّا بَشَرٌۭ مِّثْلُنَا فَأْتِ بِـَٔايَةٍ إِن كُنتَ مِنَ ٱلصَّٰدِقِينَ ﴾

“Thou art nothing but a mortal like our­selves! Come, then, forward with a token [of thy mission] if thou art a man of truth!””

(Thou art but a mortal) a human being (like us) you eat and drink just like we do. (So bring some token) a sign to prove what you claim (if thou art of the truthful) that the punishment is coming and that you are a Messenger to us.