You Finished the Cold Soba. That Pot of Cloudy Grey Water Is Not for Your Hands.

Why this phrase

Kofuku plays the tourist, Hana plays the friend who eats soba properly. He finishes his zaru soba, the small lacquered pot lands on the table, and he starts to dip his fingers in it. She stops him: that is 「そば湯」, the water the noodles were boiled in, and you pour it into whatever dipping sauce is left in your cup and drink it. Keep the claim narrow. This is a proper sit-down soba restaurant thing, not every stand-up chain, and it goes with COLD soba (もり, ざる, せいろ) because that is when you have leftover つゆ. At some shops it is brought when you are finishing, at others it sits on the table in a 湯桶 from the start. If it never appears, the line is 「そば湯、お願いします」. Comedy beat is the hand going in the pot; takeaway is the single word そば湯.