Choosing a place as a destination for immigration and staying there is mutually connected to the land facilities and the migrants' efforts. The Ash'aris came to Qom at the end of the first century (AH) and continued their collective life in this area until the middle of the fourth century (AH). This study seeks to explain the causes of migration and the continuation of the Ash'aris' settlement in the Qom region, taking into account the time factor and the possible geographical facilities. In the possibility-oriented approach, land conditions and facilities as a geographical context and the immigrants' actions as an active human factor are examined simultaneously. The emptiness of the Qom region from the presence of influential Arab immigrants allowed the Ash'aris to continue their presence there without clashing with the rival tribes. The Daylamites' attacks made it necessary to accept the Ash'aris as defensive fighting forces. The changes in the habitation and possession patterns and management of water and soil resources by the Ash'aris provided the necessary facilities for their continued residence and led to the comprehensive development of Qom.