Collected by R. Th Christiansen in Boka om Land (1921). Translated by Pat Shaw Iverson
It could be dangerous to have anything to do with the huldre-folk. Two boys found this out once. They were out herding and sat down on a hill and started whittling on their staves. Then they clearly heard someone churning inside the mountain.
"Shall we call them and ask for oatcakes with new butter, and buttermilk to drink?" said one of the boys. The other one thought they had better not, it could be dangerous. But the first boy did so all the same, and they came out with what he had asked for. But now he would not have any, so the other boy took it, and it tasted very good.
But soon the first boy who had offended them became sick. He was so poorly by the time he got home that it looked really bad; at last his father knew of no other solution than to take him back up to the mountain where this had happened. And there he had to apologize to the Huldre-folk for offending them by not eating their food.