ZMSS: He was outside chanting and hitting the moktak when suddenly his body disappeared

Here’s a little quote from the book, Dropping Ashes on the Buddha, about Zen Master Seung Sahn:

“Finally it was the last day. He was outside chanting and hitting the moktak (wooden drum) when suddenly his body disappeared. From far away he could hear the beat of the moktak and the sound of his own voice. After some time in this state, he returned to his body, and he understood: the rocks, the river, everything he could see and hear, all were his true self. The truth is just like this.”