天上落下 Fallen From The Sky
行者道：「井中河內之水，俱是有根的。我這無根水，非此之論，乃是天上落下者，不沾地就吃，才叫做無根水。」多官又道：「這也容易。等到天陰下雨時，再吃藥便罷了。」行者道：「井中河内之水，俱是有根的。我这无根水，非此之论，乃是天上落下者，不沾地就吃，才叫做无根水。」多官又道：「这也容易。等到天阴下雨时，再吃药便罢了。」
逐句解 Line by line
Pilgrim said, "Water out of a well or a river all has a root.
A well has a source in the ground; a river has a source in the hills. Both have roots. 的 is the light de.
"The rootless water I mean is not that at all. It must fall from the sky, and be drunk before it touches the ground — only that is called rootless water."
The distinction is not invented, and it is fatal. 落 is luò, to fall, where the everyday reading of the character would give là — one of a handful of places in this chapter where the two part company. 論 is lùn.
The officials said, "That is easy enough too.
They have now called both of the two vehicles easy, having been told that one of them requires the fart of a crow.
"Wait until the sky clouds over and it rains, and then let him take the medicine. That will be that."
Their solution is to wait for weather. 便罷了 is a set phrase and keeps bà, not the light ba of a softened order.
Pilgrim's answer is one clause long and it is correct. Well water and river water have a root — a source in the ground — and rootless water in his sense has to fall out of the sky and be drunk before it lands.
The distinction is real and the officials have no answer to it. So they call this easy as well, having just been told that the alternative requires a crow's fart, and propose to wait for rain. It is the second time in a handful of lines that they have declared something easy, and the second time they have been wrong.