不能得動 Why Not Wrap His Hands
八戒見了，搥胸道：「咦！那妖怪晦氣呀。捲我這夯的，連手都捲住了，不能得動；捲那們滑的，倒不捲手。他那兩隻手拿著棒，只消往鼻裡一搠，那孔子裡害疼流涕，怎能捲得他住？」八戒见了，搥胸道：「咦！那妖怪晦气呀。卷我这夯的，连手都卷住了，不能得动；卷那们滑的，倒不卷手。他那两只手拿着棒，只消往鼻里一搠，那孔子里害疼流涕，怎能卷得他住？」
逐句解 Line by line
Bajie saw it, beat his breast and said: "Well!
搥胸 — to strike the chest, a gesture of frustration rather than of grief here.
That monster has no luck at all.
晦氣 — ill luck of the clinging sort, the same word Bajie used of himself in the pond.
When he wrapped up a clumsy thing like me, he took my hands in with the rest and I could not stir;
夯 is the rammer again, Bajie applying to himself the word Wukong throws at him. 得 keeps dé — could not manage to.
and when he wraps a slippery one like that, he goes and misses the hands.
倒 reads dào — contrary to what you would expect.
With those two hands of his holding the staff, he need only jab it up the nostril. The holes will smart and stream, and how then will he keep his hold?"
得 is the light de in 捲得他住, a potential complement — manage to keep him wrapped. 搠 is to jab or thrust.
Bajie's complaint begins as pure envy — the monster is unlucky, my capture went properly, this one has been botched — and turns halfway through into the best tactical analysis anybody offers in the chapter. He works out precisely why the grip has failed and precisely what should be done about it.
He is not trying to help. He is grumbling about the unfairness of it from a hillside, in the tone of a man watching someone else's job being done badly. The sharpest observation anyone makes in this fight belongs to the character who is at that moment contributing nothing whatever.
Notice too the word he uses for himself: the rammer, the heavy blunt tool. It is what Wukong called him when he slapped him earlier in this chapter, and Bajie has adopted it. He knows what he is, and he says so while diagnosing a problem nobody else has spotted.