Laqad kana lakum fee rasooli Allahi oswatun hasanatun liman kana yarjoo Allaha (surah Ahzab: 21)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(33:21) Surely there was a good example for you in the Messenger of Allah, *34 for all those who look forward to Allah and the Last Day and remember Allah much. *35

Laqad kaana lakum fee Rasoolil laahi uswatun hasanatul liman kaana yarjul laaha wal yawmal Aakhira wa azkaral laaha kaseeraa

*34) In view of the context in which this 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. They are being addressed, as if to say: "You claimed to be the believers and Muslims and followers of the Holy Messenger. You should have seen how the Messenger whose followers you claimed to be conducted himself on the occasion. If the leader of a group is himself a seeker of personal security, is lazy and indolent, gives preference to personal interests to everything else, and is ever ready to flee danger, it would be reasonable to expect manifestation of such weakness from his followers. But here the case was different. The Holy Prophet endured along with others every toil and labour 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. After the betrayal of the Bani Quraizah his own family had also been exposed to danger even as the families of the other Muslims were. He did not make any special arrangement for his own and his family's protection, which did not exist for others. He was always in the forefront to offer maximum sacrifices for the great objectives for which he was constantly asking others to make sacrifices. Therefore, whoever made a claim of being his follower should have followed the practical example set by the leader.
This is the meaning of the verse in the context here. But its words are general and there is no reason why it should be confined to these meanings only. AIlah dces not. say that only in this respect His Messenger's life is a model for the Muslims to follow, but has regarded it as a model absolutely. Therefore, the verse demands that the 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.
*35) That is, "The Prophet's life is no model for the person who is forgetful of God, but it certainly is a model for him who remembers Allah much and consistently and not only occasionally just by chance. Likewise, this life is no model for him who has no hope from Allah and does not expect Resurrection to take place, but it is most surely a model for the person who is hopeful of Allah's grace and His favors, and who is also mindful that the Day of Judgement 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. "