(O Muhammad!) We have sent you to be a real blessing for the people of the world. Say to them, “That which is revealed to me is this: Your Deity is One Deity only. Will you, then, surrender to Him?” If even then, they turn away from it, tell them plainly, “I have warned you openly; now I do not know whether that thing with which you are being threatened is near at hand or far off. You should, however, note it well that Allah has the knowledge of what is uttered aloud and also of what you talk about secretly.
(Al-Qur’ān – 21:107-10)
The Qur’ān makes it clear that Muhammad (peace and blessings of Allah be to him) was Allah’s Messenger for all human beings. Here it asserts that he was sent as a “real blessing” for the people of the world. It means the appointment of Muhammad as His Messenger was a blessing and mercy of Allah to the whole world. This is because he awakened the neglectful world from its heedlessness and gave it the criterion between truth and falsehood and warned it very clearly of both the ways of salvation and ruin.
This fact has been stated here to tell the disbelievers of Makkah that they were quite wrong in their estimate of the Holy Messenger that he was an affliction and distress for them. They have been told, “O foolish people, you are wrong to presume that he is an affliction for you; he is in reality a blessing and mercy of Allah for you.”