I Did Not Die

I recently watched a episode of a TV series with Detective Superintendent Jane Tennison (played by Helen Mirren), where this poem was read at a funeral:

I Did Not Die

Don't stand beside my grave and weep,
For I'm not there, I do not sleep,
I am a thousand winds that blow,
I am the diamond's glint on snow,
I am the sunlight on ripened grain,
I am the gentle autumn's rain.

When you awaken in morning's hush,
I am the swift uplifting rush,
of quiet birds in circle flight,
I am soft stars that shine at night,
Don't stand beside my grave and cry,
I am not there. I did not die.