Кто знает, что это за произведение?

...
Then they started questioning-
Had he noticed anything?
First, in prayer he bent his head,
Through his teeth, he slowly said
(After bowing left and right):
"Why, I never slept all night!
And I really wonder whether
There was ever colder weather!
It was cold, I'd have you know-
I kept running to and fro-
Wasn't it a chilly night!
But, then, everything's all right.
" And his father said with pleasure:
"You, Gavrilo, are a treasure."

Evening once again drew near,
Now the third should don his gear,
But he never turned a hair,
Sitting on the oven there,
Singing with his foolish might:
"0, you eyes, as black as night!"
Then to coax and beg Ivan
Both the elder sons began;
Bade him go and guard the grain;
They grew hoarse-but all in vain.
Father finally said: "Here,
You just listen, Vanya dear,
Go on watch, and if you do,
This is what I'll do for you:
I shall give you beans and peas,
And some pictures, if you please."

At these words, Ivan climbed down,
Donned his coat of russet brown,
Pocketed a lump of bread
And on sentry-go he sped.

Night fell and the white moon rose.
On his beat Ivan now goes,
Looking sharply all around;
Then he sits upon the ground,
Munching slowly at his bread,
Counts the bright stars overhead.
Suddenly, a neigh resounded-
To his feet our sentry bounded;
Peering round with shaded eyes,
In the field a mare he spies.
Now, this mare, I'd have you know,
Whiter was than whitest snow,
Silken mane in ringlets streaming
To the ground, all golden gleaming...