Buddhist memorial services were customarily held seven times every seven days, because the bereaved family could pray to the Juo for seeking commutation for the dead person at every trial, while additional memorial services held in line with the additional three trials supposedly functioned to save all dead persons.
なお、仏事の法要は大抵七日ごとに七回あるのは、審理のたびに十王に対し死者への減罪の嘆願を行うためであり、追加の審理の三回についての追善法要は救い損ないを無くすための受け皿として機能していたようだ。