Answer:
This is rectangular, hollow and has a lid, and where you’ll find it you might wonder, it is just six feet under. What is it?
Walk on the living, they don’t even mumble, Walk on the dead, they mutter and grumble. What are they?
It stands upright and can be quite grand. Its secret is not hidden but right at hand. What is it?
A mile from end to end, yet as close to as a friend. A precious commodity, freely given. Seen on the dead and on the living. Found on the rich, poor, short and tall, but shared among children most of all.
What can you share and still have all for yourself?
I start with T end with T and within me is T.