The Pilgrim said: 'My somersault, when all's said, is only cloud-riding too — it just covers more ground, or less.'

The monkey begins by giving away his own advantage. 好道也是駕雲, 'when all's said, it is cloud-riding too': his 觔斗 (斗 dǒu) differs from Bajie's cloud in range, not in kind. Whatever stops one will stop the other, so the somersault cannot be the loophole.

'If you can't carry him, how am I to carry him either?'

馱不動 … 馱得動, 'cannot carry' against 'can carry' (得 de, the little particle of possibility). He has just levelled himself with Bajie and closed the escape route.

'As the old saying has it: "To move Mount Tai is as light as a mustard seed; but to bear a mortal is to be unable to escape the red dust."'

And now the pivot of the chapter, quoted as a proverb: 遣泰山輕如芥子，攜凡夫難脫紅塵 — 'to shift Mount Tai is lighter than a mustard seed; to carry a common man is to be unable to slip free of the red dust.' The 芥子 (with 芥 as jiè and 子 as zǐ) is the mustard seed of Buddhist parable, the standard image for the smallest thing there is. The couplet says the adept can toss a mountain about like a seed — and still cannot lift one ordinary man, because what makes the man heavy is not mass. It is 紅塵, the 'red dust': the whole clinging world of ordinary human life and its consequences. That is a weight no amount of power can take off somebody else's back.

'Now a vile fiend like this may use his snatching arts and conjure a gust of wind, but that is a matter of dragging and hauling — going along the ground; he cannot bear a man off through the air.'

攝法 is the art of snatching, the magic by which demons carry people off. But look at how it works: 扯扯拉拉，就地而行 — tugging and hauling, along the ground. Even abduction is earthbound. Lifting a mortal 空中而去, off through the air (得 de), is a different order of thing altogether.

'Tricks of that sort old Sun can use and work too; and the arts of invisibility and of shrinking the ground — old Sun knows every one.'

隱身法, the art of vanishing, and 縮地法, the art of folding up the distance between two places (那 nà twice; 還 hái). He is not pleading incapacity. He knows every one of these, and admitting it is what makes the next line bite.

'But the master is bound to pass through every strange land, and cannot yet transcend the sea of suffering — and so he cannot advance a single step by such means.'

Here is the doctrine, stated plainly. 窮歷異邦, 'to go through every foreign land to the end of it,' and 超脫苦海, 'to rise clear of the sea of bitterness.' The master has not yet done the second, so he must do the first — on foot. 寸步難行, 'hard to go an inch' (難 nán, 行 xíng), is still everyday Chinese for being completely stuck, and here it is being used with its literal meaning switched back on. The pilgrimage is not a distance. It is a course of training, and training cannot be delivered.

'You and I can only serve as his escort, keeping his body and life secure; we cannot undergo these torments in his stead, nor can we fetch the scriptures for him;

擁護, to surround and protect — the disciples are an escort, and an escort is all they are. Then the two parallel negatives: 替不得, cannot take his place, and 取不得, cannot fetch on his behalf (得 de throughout). They may keep him alive. They may not do the work for him.

'and even if one of us had the power to go ahead and see the Buddha, that Buddha would not readily hand the scriptures over to you or me.'

那佛也不肯, 'that Buddha would not consent' (那 nà; 佛 is fó). Even if the monkey flew ahead and asked nicely, the scriptures would not be handed over. They are not freight. They go to the one who earned the journey.

'It is just as they say: "What is got too easily is held too lightly."'

若將容易得，便作等閑看 — 'if a thing is got easily, it will be held as nothing' (將 jiāng, 得 de). English says easy come, easy go, which is about losing things; this is sharper, and about valuing them. It is also the novel's whole economic theory in ten characters: the difficulty of the road is not an obstacle to the scriptures' worth, it is the guarantee of it.

The Idiot, hearing this, murmured his assent and took it in.

喏喏聽受: 'yes, yes,' he heard it and took it in (那 nà). Bajie argues with everything. Here he does not, and the silence is the strongest endorsement the passage could give.

So they ate a little plain vegetarian food without relish, and master and disciples took their rest below the eastern cliff of the River of Flowing Sands.

無菜的素食 is vegetarian food with nothing to go with it — no side dishes, a thin supper — and 歇在流沙河東崖, rest on the eastern cliff of the Flowing Sands. The day of unaided effort ends on short rations and a night on the bank, which is about the right note for it.