Volsunga Saga - Chapter XLIII: The Latter End of all the Kin of the Giukings Unknown Author (Ft. Translated by William Morris and Eirikr Magnusson)

Now telleth the tale concerning the sons of Gudrun, that she had arrayed their war-raiment in such wise, that no steel would bite thereon; and she bade them play not with stones or other heavy matters, for that it would be to their scathe if they did so.

And now, as they went on their way, they met Erp, their brother, and asked him in what wise he would help them.

He answered, "Even as hand helps hand, or foot helps foot."

But that they deemed naught at all, and slew him there and then. Then they went their ways, nor was it long or ever Hamdir stumbled, and thrust down his hand to steady himself, and spake therewith --

"Naught but a true thing spake Erp, for now should I have fallen, had not hand been to steady me."

A little after Sorli stumbled, but turned about on his feet, and so stood, and spake --

"Yea now had I fallen, but that I steadied myself with both feet."

And they said they had done evilly with Erp their brother.

But on they fare till they come to the abode of King Jormunrek, and they went up to him and set on him forthwith, and Hamdir cut both hands from him and Sorli both feet. Then spake Hamdir --

"Off were the head if Erp were alive; our brother whom we slew on the way, and found out our deed too late." Even as the Song says, --

"Off were the head
If Erp were alive yet,
Our brother the bold,
Whom we slew by the way,
The well-famed in warfare."