From Íslenskar Þjóðsögur og Sagnir, vol. 3. collected by Sigfús Sigfússon, pp. 465-466.
Ástagaldur (‘Love Magic’)
Close to 1820 there was a farm in Eyjafjörður, where there were two teenage boys who were learning magic. One evening in the twilight, one of them comes in, walks to a girl who is there, and gives her a big kiss. She thought this was rather strange, especially because she heard something rattling in his mouth,¹ and thinks also that there is some change in herself. She gets up some courage and says “If there is anybody here who is trying to mess with me, it shall land on the sheep on the floor,” because there were both a young ram and young ewe.² Then it happened that the ewe went crazily into heat and would not leave the ram alone the entire evening. When the girl saw what happened, and that from herself disappeared all passion, she pushed the man so hard to tell her what tricks he had tried to pull, that he confessed to her that he had a lead plate with a magical stave carved in it under the root of his tongue, and he had kissed her to get her appreciation.
It is so told about one southern traveler that it was his custom that he stayed in farms to give people a bite from his provisions. Once he stays on a farm and does what he is used to. Among other things, he gives a pretty woman who is there a bit of a bread cake. She accepted the cake gladly, but secretly she breaks it all down and gives it to a female dog which was in the home. Now it is bedtime, but around the time when people are asleep, the bitch comes to the bed of the traveler and tries to get up to his bed. This goes on all night. Early morning he went away and there is nothing more to tell about him.
¹ Casual mouth-to-mouth kissing is, I’m told, traditionally seen as normal in Iceland, so this might not have been considered suspicious if not for the sound.
² In old times, in order to conserve heat, some Icelandic turf houses kept animals on the ground floor, with a flat platform above it where the people lived.
Without actually suggesting anything, I wonder about the relationship between a woman transferring a love spell to a bitch in folklore has with Hávamál.