Why did Muhammad Ahmad al-Mahdi establish a hermitage on Aba Island?

Muhammad Ahmad al-Mahdi established a hermitage on Aba Island to practice religious asceticism and to separate himself from the official ruling class and the orthodox religious hierarchy.12

As a youth, he moved away from traditional, formal religious education toward a mystical interpretation of Islam within the Sufi tradition. By moving to the island in 1870 with his disciples, he sought to pursue a life of self-denial and deep study of the Qur'an under the discipline of a religious brotherhood, free from the worldliness he perceived in the official religious establishment.21