The Eight is execution; the Nine is the last stretch before execution completes. Nine is three threes: the Three was first form, and the Nine is that form pushed to its fullest. So Nines in every suit are about approaching saturation — Nine of Cups seated content before nine cups, Nine of Pentacles alone in the garden enjoying it, Nine of Wands bandaged and still on watch, Nine of Swords sitting up in the middle of the night.
You can see the Nines split in two: Cups and Pentacles are harvest, Wands and Swords are cost. That's not a contradiction, it's two faces of one thing — whoever has reached a Nine has something in hand and has already paid a great deal for it. It's the most honest rank on the line: it shows you the result and the bill at once.
Where you'll recognise it: nearly done and very tired, having what you wanted and feeling alone with it, waking at night over the one part still unfinished. Running well, a Nine is maturity: you know what you have and what it cost. Stuck, its problem is over-holding — the Nine of Wands can stand watch long after the enemy has gone.
