護法降魔 We Need Ours for the Road
八戒道：「好好好，說得有理。我們的器械，一則你們使不得，二則我們要護法降魔，正該另造另造。」八戒道：「好好好，说得有理。我们的器械，一则你们使不得，二则我们要护法降魔，正该另造另造。」
逐句解 Line by line
Bajie said, "Good, good, good — that is well said.
Three 好 in a row, which is Bajie all over: enthusiastic agreement before anyone has thought it through. 得 is de in 說得有理, the hinge tying the speaking to how reasonable it was.
Our own gear you cannot handle, for one thing; and for another we need them to guard the dharma and subdue demons. Fresh ones are just the thing to have made."
一則 and 二則, firstly and secondly, is a plain enumerating construction and it makes Bajie sound briefly like a man laying out an argument. 得 is de again in 使不得. 降 is xiáng, subduing — the chapter's tenth and last xiáng of eleven. And 護法降魔, guarding the dharma and subduing demons, is the job description of the whole pilgrimage.
Bajie is the one who says yes, and he gives two reasons, both of them correct. The princes cannot use these weapons, and the pilgrims are going to need them.
The second reason is the one the chapter's last page turns on. He says out loud that they must keep their weapons because there are demons ahead, and then agrees to leave all three in a builder's yard.