Thor took hold of the handle of his hammer so hard that his knuckles grew white. As might be expected, the bonde and all his household cried aloud and sued for peace, offering him as an atonement all that they possessed. When he saw their fear, his wrath left him. He was appeased, and took as a ransom the bonders children, Thjalfe and Roskva. They became his servants, and have always accompanied him since that time.

- Prose Edda (The Fooling of Gylfe, XIV)