Since there is only one undifferentiated nature of all appearance, it has to be realized as already being the only truth that there is; it cannot be attained as something not yet realized. His style is summarized in the phrase kigen kikō, ‘strange words and extraordinary actions’, which became a model for other Zen masters.
"Ma-tsu Tao-i." The Concise Oxford Dictionary of World Religions. . Encyclopedia.com. (November 15, 2018). https://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/ma-tsu-tao-i
"Ma-tsu Tao-i." The Concise Oxford Dictionary of World Religions. . Retrieved November 15, 2018 from Encyclopedia.com: https://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/ma-tsu-tao-i