摩訶止觀 3.9

3.9

As for the meaning of piercing through: wisdom takes effect and pierces through to destroy defilements. The Great Sūtra says: 'A sharp hoe digs into the ground through boulders and gravel, straight down to the diamond.' The Lotus Sūtra says: 'Digging into a high plateau, one still sees dry earth; applying effort without cease, one gradually reaches mud.' This receives its name from that which is destroyed; this establishes the contemplation of piercing through.