If you, sir, really are mindful of the Buddha, just be mindful that your own nature is Amitābha. In the twenty-four hours of the day and within the four awe-inspiring deportments, take the letters of the name Amitābha Buddha and hang them in front of your mind’s eye, and the mind’s eye and the Buddha’s name form one piece.
Mind after mind continues with this, and when thought after thought/moment it is not neglected, closely reflect on “Who is the person being mindful?” If you have perfected the study technique over a long time, then unexpectedly in a moment, the mind and its thoughts will be cut off and eliminated, and the true body of Amitābha Buddha will firmly appear in front of you.
At this very time you will believe the words “From of old the immovable is named buddha.”
Excerpt from Instructions to Layman Nag-am on the Essentials of Mindfulness of the Buddha, found in Collected Works of Korean Buddhism, Vol 8-1, by Master Taego Bowou, Dharma Heir of Chan master Shiyu Qinggong from the Linji school.