When would this phrase be used in Japanese: 回光返照?

Question:

I believe it means something like a final surge of activity before dying.

When would someone use that though? What sort of context?

Answer:

It is not Japanese. It should be Chinese.

<Sorry. Here is a correction>
Yeah I have checked to find that it is a concept used in a faction of Zen which originates in China some 750 years ago. A kind of Commandment?

What I have found is: Its literal meaning: the sky brightly glows in the west refecting the sunlight when the sun goes down. Thence it means: Rather than looking at things outside, look at your own inner self and grasp the truth. (Try not to look for the way outside but try to confront yourself and grasp the very nature of yourself.)

<Mr Watanabe> You are so knowledgeable! I was not able to find when, how and in what context the "Commandment" is used.