The topi(hat) hold a very high status in Islam.
It serves to show that the wearer is a Muslim, thereby distinguishing him from the followers of other religions. Islam lays great stress of the protection of our Islamic identity and the topi goes a long way in ensuring this.
It is a sign of the humility of the wearer and his reverence before Allah.
It has been the practice of the Prophets of Allah (A.S) and the pious ones throughout the ages, thus by adopting the topi, one is showing that his affiliations lie with those who are the friends of Allah and not with the friends of Shaytaan (Satan).
And most importantly, the topi was the practice of our beloved Prophet (Sallallahu Alayhi Wasallam). Just as people who love a certain hero or star will unquestioningly adopt the dress and habits of their idol, we Muslims in our deep-rooted love for our beloved Prophet (Sallallahu Alayhi Wasallam) endeavor to follow him in his every action and habit, regardless of whether we find any “wisdom” or reason behind it. His doing it, is sufficient a wisdom for us.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai