Prophet Muhammad was sent as a role model for all humanity

Surah Al-Ahzab discusses the important event of the Battle of the Trench (or Al-Ahzab: the Clans), which took place in Shawwal, 5 A.H. In view of the context in which the following verse occurs, the object of presenting the Holy Prophet’s conduct and way of life as a model was to teach a lesson to the people, who had been motivated by considerations of selfish interests and personal safety on the occasion of the Battle of the Trench. The below verse contains an important principle for all Muslims, i.e. to follow the Messenger of Allah in all his words, deeds, etc.

Indeed in the Messenger of Allah (Muhammad) you have a good example to follow for him who hopes in (the Meeting with) Allah and the Last Day and remembers Allah much.
Quran (Surah Al-Ahzab, Verse 21)

Reflections from this verse
In this verse, Allah presents His Messenger’s life as an absolute model for the Muslims to follow on the day of Al-Ahzab, with regard to patience, striving and waiting for Allah to provide a way out of the challenge that he was in.
Allah sets the Prophet’s example for those who were anxious and impatient and were shaken by feelings of panic on the day of Al-Ahzab.
The verse demands that Muslims should take the Holy Prophet’s life as a model for themselves in every affair of life and should mould their character and personality according to it. This, therefore, means that those who claim to be the believers and Muslims and followers of the Messenger, should see how the Messenger conducted himself on the occasion.
The Holy Prophet set the best example in leadership. He endured along with others every toil and labor that he asked others to endure, and endured better than others; there was no trouble which others might have experienced and he himself did not. He was among those who dug the trench, and endured hunger and other afflictions just as the common Muslims did. He did not leave the battlefront even for a moment during the siege nor retreated an inch.
The Prophet’s own family had also been exposed to danger just as the families of other Muslims. He did not make any special arrangement for his own and his family’s protection. He was always in the forefront to offer maximum sacrifices for the great objectives for which he was constantly asking others to make sacrifices.
The Prophet’s life is a model for him who remembers Allah much and consistently and not occasionally, just by chance.
His life is a model for the person who is hopeful of Allah’s grace and His favors, and who is also mindful that the Day of Judgment will come when his well-being will wholly depend on how closely his conduct resembled the conduct and character of the Messenger of Allah in this world.

(References: Sayyid Abul Ala Maududi – Tafhim al-Qur’an and Tafsir Ibn Kathir)