From: UT:
And one day, as Tuor sat upon the shore, he heard the rush and whine of great wings, and he looked up and saw SEVEN white swans flying in a swift wedge southward.
…… and he took the SEVEN feathers(of the swans) and set them in the crest of his
helm……
Now Tuor journeyed south along the coast for full SEVEN days……
Voronwe: I will not darken your heart son of
Middle-earth, with the tale of my labour SEVEN years in the Great Sea from the North even into the South……
"Yea, indeed," said Voronwë; "to a stranger it might seen that pride has made the servants of
Turgon pitiless. Long and hard seem the leagues of the SEVEN Gates to the hungry an wayworn."
SEVEN great pillars of steel there were, tall with the height and girth of strong young
trees, but ending in a bitter spike that rose to the sharpness of a needle; and between the pillars were SEVEN cross-bars of steel, and in each space SEVEN times SEVEN rods of steel upright, with heads like the broad blades of spears……..
…. Silent upon either hand stood a host of the army of Gondolin; all of the SEVEN kinds of the Seven Gates were there represented; but their captains and chieftains were upon
horses, white and grey.