Bottling yawns

Sometimes,
I wish I could bottle yawns

And stop any sleep

So I could be yawnless,

for a good while more

Then,

When the mood took me

I would uncork

Let loose the yawn 

And slumber again

Yet,

Capturing a yawn

Would take practice

It would not be possible

For one too far gone

But,
If my mind were right

The dark were not too strong
I could seize my chance

Capture a yawn

And,
Use my bought time well
Until the debt is due
And I set
the 

yawn
free
.