In the story of Odin acquiring Suttung's mead Odin kills nine serfs when he throws his hone into the air. The serfs who all want to own this valuable sharpening tool wind up cutting each others throats. Odin, (Bolverk), then tells Baugi that he will do the work of the nine serfs if he, as his wages, helps him get a drink of the Suttung's mead.
In Voluspa, the seer says, " I know how nine roots form nine worlds, under the Earth, where the ash tree rises...." Also from Voluspa we are told, " Far famed Thor, the son of Earth, the son of Odin, goes forth to fight the snake. Midgard's defender dies in triumph, but the human race no longer has a home. Nine steps beyond the serpents body, Thor wounded walks in pride."
In Gylfaginning, the great guardian of Asgard, Heimdall says, " Of nine mothers I am the son, and son of nine sisters too." Also from that same book we get from Njord, " Mountains I loathed, no longer then nine nights did I stay there, the howling of the wolves seemed ugly to me compared to the hooping of swans." One of the stories in Gylfaginning has this to say about Valhalla: "Out of a single door at a time will trample nine hundred and sixty men."
Odin has several stories that use this magical number nine. In Havamal he says, speaking as Har, " I know that I hung on a wind - swept tree for nine long nights, pierced by a spear...." He later goes on to say, " Nine mighty songs I learned from the son of Bolthorn, Bestla's father." We also have this about the ring Draupnir. "Odin laid on the pyre the gold ring which is called Draupnir, it had this characteristic afterwards, that every ninth night there dropped from it eight rings of equal value."
In Skirnismal Freyr has to wait nine long nights to wed Gerd, leading him to say: " A night is long, longer are two, how will I endure three? Oft to me a month seemed shorter than half this honeymoon."
In Skaldskaparmal there is this line from the duel between Thor and Hrungnir, " Then the giants made a man of clay at Grjotunagardar. He was nine leagues high and three wide."
The Lay of Hymir: "There Tyr found his fearsome grandmother, she had nine hundred ugly heads."
The Lay of Fjolsvip: " Tis Laevatein hight, which Loki did forge Nifhel beneath in an iron kettle keeps it. Sinmara there holds it in hard locks nine."
The Lay of Volund : And the ninth, (year), could remain no longer. The maidens wanted to go through Mirkwood, young Valkyries on their way to war."
The Lay of Helgi Hjorvardsson: (About their son)," Strong and handsome, he never spoke much, and no name would stick to him. He was sitting on a grave mound when he saw nine Valkyries riding." From the same story we read: " Witch who was your father, you should be buried nine leagues below the earth growing barley on your breast." And a third line: " Three times nine they came but one commanded, a white maid wearing a helmet.
The First Lay of Helgi Hunding's Bane: " Nine wolves you brought into the world on Saga Ness and I sired them all."
The Second Lay of Helgi Hunding's Bane: " Then they saw nine Valkyries riding through the sky."
The Mill Song: "For nine years we did nothing but play beneath the Earth where we grew up."
Also Hermod rides for nine nights to ask Hel to free Baldr from Niflheim, and Aegir and Ran have nine daughters.
Ok, thats enough examples. I think I have shown the importance of the number nine in the stories of the Eddas, both the books of the Gods and the books of the princes. I believe, as do others, that the number nine is a sacred number for the Gods and Goddesses and therefore is a sacred number for us here in Midgard. I am not sure how it came about, but if you notice almost all of our martyrs and heroes are honored on the ninth day of the month. Does this number have some magical power ? I don't know. I do know that I feel more confident when I see this number in my daily life. The number nine, sacred yes, magical, maybe .
Go with Odin's wisdom, Freyja's love and Thor's protection !