The skaldic periphrasis for "woman" just cited is a complex puzzle, involving allusion, substitution, and a grammatical trick. The limiting element is not a single word, but is itself a substituting periphrasis: "enforced ransom of the otter" stands for the concept "gold," in allusion to the ransom which three of the Æsir were compelled to pay Hreiðmarr for the killing of his son Ottarr, the gold of the ransom having itself been taken by force from Andvari. Woman is conceived as the giver of gold, selja gulls. Having periphrased the concept "gold" (gull) by ótrs nauðgjöld, the skald then substituted for the word selja, "giver" -- which also means "willow" -- the word eik, which, like selja is a feminine tree-name. But there is a difference between the character of the puzzle involved in periphrasing "gold" as "enforced ransom of the otter" and that presented by "oak" for "giver": the first is a mythological allusion, and in the myth gold was a ransom demanded and paid under duress -- gold is characterized as something which, in a given context, it actually was. But a giver is not an oak: woman, as giver, is called something which woman is not. And here, in the identification of a person or thing with something that it is not, except in a very special and artifical sense, lies the nature of the true kenning; a kenning is not merely a metaphor; it is, in Heusler's words, metapher mit ablenkung.