十二個紅棗 Twelve Red Dates
內一女子急拿了一把等子道：「稱出一分二釐，分作四分。」卻拿了十二個紅棗兒，將棗掐破些兒，揌上一釐，分在四隻茶鍾內；内一女子急拿了一把等子道：「称出一分二厘，分作四分。」却拿了十二个红枣儿，将枣掐破些儿，揌上一厘，分在四只茶钟内；
逐句解 Line by line
One of the women snatched up a steelyard. "Weigh out one fēn two lí," she said, "and divide it into four portions."
Do the arithmetic, because the text expects you to. A 分 is ten 釐, so one 分 two 釐 is twelve 釐. Divided four ways, that is three 釐 a portion — exactly the dose he specified twenty-one characters earlier for a monk with some attainment. The figures are not decorative. They balance. 稱 is chēng, to weigh out.
Then he took twelve red dates, pinched each one a little open, stuffed in a lí apiece, and shared them out among four tea cups;
And the arithmetic closes. Twelve dates, one 釐 in each, four cups — three dates to a cup, three 釐 to a cup. The chapter never states the three-per-cup figure here, but it confirms it much later, when Eight Rules looks into his cup and sees 三個紅棗兒. 掐 is qiā, to nip between the nails; 揌 is to stuff or pack in. A red date is sweet, wrinkled and dark enough to hide anything.
Everything in this passage checks. One fēn two lí is twelve lí; twelve lí across four cups is three each; twelve dates across four cups is three each; and three lí is the dose he named for a monk with attainment. Ming vernacular fiction is not usually this careful with numbers, and when it is, the care is doing something.
What it is doing is making the reader complicit. We now know the dose, the carrier, the count and the distribution. We could describe the murder weapon to a magistrate. The four men it is meant for are outside looking at trees.
The red date is a horribly good choice, and the book knows it. It is the sweet you put in a guest's tea to be hospitable — wrinkled, dark, sweet enough to cover anything, and completely unremarkable at the bottom of a cup. Nobody inspects a date.