原文 Original text
繁體 Traditional
Reader's edition
不知深淺 He Does Not Know The Depth
那老者笑道：「這和尚不知深淺。那三個魔頭，神通廣大得緊哩。那老者笑道：「这和尚不知深浅。那三个魔头，神通广大得紧哩。
逐句解 Line by line
那老者笑道：「這和尚不知深淺。
那老者笑道：「这和尚不知深浅。
The old man laughed. "This monk has no idea how deep the water is.
不知深淺 is not to know the depth — of water, and so of anything. It is still exactly what you say about somebody who has walked confidently into a situation he has not measured.
那三個魔頭，神通廣大得緊哩。
那三个魔头，神通广大得紧哩。
Those three demon chiefs have powers that are very great indeed."
得緊 is the degree complement again — great, and to what extent? — with 得 unstressed. The old man said exactly this to Pilgrim too, thirteen hundred characters back, and is about to explain why it is not the point.
The laugh is the tell. The old man has stopped being frightened of these creatures and started being exasperated by them, which is a considerable shift in a man who was on the ground twice.
His idiom is precise. Not knowing the depth is not the same as being wrong — Bajie's arithmetic may be perfectly good. It is that he has not measured the thing he is about to wade into, and the next passage is the measuring.