Frá dauða Sinfjǫtla, although published in editions of the Elder Edda, is not a poem, but a very short piece in prose, describing the death of Sinfjǫtli, son of Sigmundr, connecting Helgakviđa Hundingsbana II and Grípisspá .
Borghildr, wife of Sigmundr, wanted Sinfjǫtli, her stepson, dead, as Sinfjǫtli had killed her brother. Now it is said, that Sigmundr was so tough, that he could withstand any kind of poison, but his sons could only tolerate it on their skins. Borghildr gave them ale, which Sinfjǫtli recognized as poisoned. He excused himself for two rounds, but when she brought him the third horn, his father, now drunk, said: "Let your beard filter it, son!" Sinfjǫtli drank and died at once.
