見風即長 Why Does It Grow in the Wind
三個小王子禮拜道：「豬師、沙師之兵，俱隨身帶在衣下，即可取之。孫師為何自耳中取出，見風即長，何也？」三个小王子礼拜道：「猪师、沙师之兵，俱随身带在衣下，即可取之。孙师为何自耳中取出，见风即长，何也？」
逐句解 Line by line
The three young princes bowed and said, "Master Zhu's and Master Sha's weapons are both carried about the body under the clothes and can simply be taken out.
The boys have been observing closely, and they have noticed something a casual reader might not: two of the three weapons are ordinary objects kept under a coat, and one is not. 豬師 and 沙師, Master Zhu and Master Sha, are the courteous surname-and-title forms their father first used, and the sons have picked them up.
Why does Master Sun bring his out of his ear, and why does it grow the moment it meets the wind?"
A properly formed question, and the first piece of curiosity anybody in Yuhua has shown about how any of this works. 為何 at the start and 何也 at the end is a doubling of the asking, which gives it the sound of genuine puzzlement rather than politeness. It is also the cue Pilgrim has been waiting for.
The boys have spotted the anomaly and asked about it, which is more than the officials, their father, or Tripitaka has managed.
It is a good question, too. Two weapons behave like objects and one behaves like a spell, and the difference is real: the rod is older than the other two by an order of magnitude, and Pilgrim is about to say so at length.