Faun, "Egil Saga". This tells parts of a story from Egils Saga, an Icelandic saga about Egil, who is something of a rebel without a cause. The full story:
While they sat at meat Egil saw that a woman lay sick on the daïs at the ends of the hall. He asked who was that woman in such sad case. Thorfinn said she was named Helga, and was his daughter; she had long been ill; her complaint was a pining sickness; she got no sleep at night, and was as one possessed.
'Has anything,' asked Egil, 'been tried for her ailment?'
'Runes have been graven,' said Thorfinn; 'a landowner's son hard by did this; and she is since much worse than before. But can you, Egil, do anything for such ailments?'
Egil said: 'Maybe no harm will be done by my taking it in hand.'
And when Egil had finished his meal, he went where the woman lay and spoke with her. Then he bade them lift her from her place and lay clean clothes under her, and they did so. Next he searched the bed in which she had lain, and there he found a piece of whalebone whereon were runes. Egil read them, then cut the runes and scraped them off into the fire. He burned the whole piece of whalebone, and had the bed-clothes that she had used hung out to air. Then Egil sang:
'Runes none should grave ever
Who knows not to read them;
Of dark spell full many
The meaning may miss.
Ten spell-words writ wrongly
On whale-bone were graven:
Whence to leek-tending maiden,
Long sorrow and pain.'
Egil then graved runes, and laid them under the bolster of the bed where the woman lay. She seemed as if she waked out of sleep, and said she now felt well, but she was weak. But her father and mother were overjoyed. And Thorfinn offered to Egil all the furtherance that he might think needful.
You can find the exact lyrics and their translation here.