Because "Amida-kyo Sutra" is the sutra whose content is the teachings preached that Shakyamuni had taught, not the one in which Shakyamuni replied to the questions raised by disciples, it is called 'Mumon jisetsu kyo' (the sutra whose content is not questions and answers but the preaching of Shakyamuni).
『阿弥陀経』は、弟子の質問に答える形の経ではなく、釈迦自ら説かれた経であるため「無問自説経」ともよばれる。