According to Snorri Sturluson in Gylfaginning, the first of the three fetters with which the Æsir attempted to bind the wolf Fenrir. Because the wolf was fated to be their destruction, the Æsir sought a way to incapacitate him:
They made a very strong fetter, which they called Lædingr, and brought it before the Wolf, bidding him try his strength against the fetter. The Wolf thought that no overwhelming odds, and let them do with him as they would. The first time the Wolf lashed out against it, the fetter broke; so he was loosed out of Lædingr.
Snorri says that it passed for proverb, "to loose out of Lædingr," when anything was exceeding hard.
- Gylfaginning, 34.