In Equal Sacrifice Robert Frost

Thus of old the Douglas did:
He left his land as he was bid
With the royal heart of Robert the Bruce
In a golden case with a golden lid,

To carry the same to the Holy Land;
By which we see and understand
That that was the place to carry a heart
At loyalty and love's command,

And that was the case to carry it in.
The Douglas had not far to win
Before he came to the land of Spain,
Where long a holy war had been

Against the too-victorious Moor;
And there his courage could not endure
Not to strike a blow for God
Before he made his errand sure.

And ever it was intended so,
That a man for God should strike a blow,
No matter the heart he has in charge
For the Holy Land where hearts should go.

But when in battle the foe were met,
The Douglas found him sore beset,
With only strength of the fighting arm
For one more battle passage yet—