The volva and her herbs

"In a sad voice, Sigurd's mother began to sing, followed by the rest of the women.

It was a song about Freya, daughter of Njord, the goddess of love. The lay caused people to sway, moving to and fro. They sang it slowly, there, inside the hall, they lamented Freya's love of Od.

The song turned really sad when Od ran away. "Where is Od?" the women moaned in the song. In the glowing light of the pit fires, his mother changed into a volva, offering herbs to the flames. Making a flash, the burning leaves filled the room with a heavy and sweet-smelling smoke.

The lay was arousing, and soon the men fell in, enchanted. They all sang about Freya's longing, and the song was for Njord, the god who brought the grain – and the bjor."
(From The Slayer Rune)