E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
He has sown his wild oats. He has left off his gay habits and is become steady. The thick vapours which rise on the earths surface just before the lands in the north burst into vegetation, are called in Denmark Lok kens havre (Lokis wild oats). When the fine weather succeeds, the Danes say, Loki has sown his wild oats.