The Name of Amida Buddha severs the mind of darkness, which is the root cause of suffering, in a split second of ichinen. Write the words of Master Shan-tao that explain how sharp it is.
A sharp sword: such is the Name of Amida.
The Name, Namu Amida Butsu, which was made by Amida Buddha, has the tremendous power to cut and kill the mind of darkness, which is the root cause of the delusion that has kept us transmigrating for untold aeons. This is why Master Shan-tao praises the Name highly as a “sharp sword.”
(from the doctrine book, 3-45 of)