From Gylfaginning, part of Snorri Sturluson´s Prose Edda.

“Loki took Mistletoe and pulled it up and went to the Thing.

Hödr stood outside the ring of men, because he was blind. Then spake Loki to him: ‘Why dost thou not shoot at Baldr?’ He answered: ‘Because I see not where Baldr is; and for this also, that I am weaponless.’ Then said Loki: ‘Do thou also after the manner of other men, and show Baldr honor as the other men do. I will direct thee where he stands; shoot at him with this wand.’ Hödr took Mistletoe and shot at Baldr, being guided by Loki: The shaft flew through Baldr, and he fell dead to the earth; and that was the greatest mischance that has ever befallen among gods and men.” — Brodeur’s translation