According to 'Senjusho' (a compiled Buddhist tales of 13th century) by Saigyo Hoshi (Buddhist priest Saigyo), a long time ago, someone asked the virtuous Buddhist priest Kuya how nenbutsu should be practiced, and he said nothing but 'By throwing out.'
むかし、空也上人へ、ある人、念佛はいかが申すべきやと問ひければ、「捨ててこそ」とばかりにて、なにとも仰せられずと、西行法師の「撰集抄」に載せられたり。