On an occasion of sharing by two venerable masters with their disciples.
Elder Master Chanyun: Layman Dong was an old man who stayed in Zhanshan Monastery as a language teacher. He was reciting Amitabha in a room when they called him to come out for mealtime.
Elder Master Mengcan: No, no-one called him. He recited Amitabha and simply exited the room. The door was locked. He locked the door from within but he left the room while reciting Amitabha. I was staying there at that time. I was there when this happened. This happened around 1938-39. I did not leave the monastery yet.
Elder Master Chanyun: So what happened was that: he entered his room and locked the door from within to prevent anyone else from entering. Then he recited Amitabha until a state of one-pointedness. Without opening the door, he went out of the room. Later, when he returned to his room, he couldn’t open the door because the door was locked from within. (Audience laughed)
Elder Master Mengcan: This is the state of “one-pointed undistracted mind”. It is “Form is emptiness; emptiness is form” (from Heart Sutra). His body-mind was empty, the external structure of the room was empty. He recited until all that remained was just that one phrase "Amitabha". Nothing else existed for him. In this state of union, he could pass through the door and leave the room.