一日為師 One Day A Teacher
三藏道：「我如今起坐不得，怎麼上馬？但只誤了路啊。」行者道：「師父說那裡話。常言道：『一日為師，終身為父。』三藏道：「我如今起坐不得，怎么上马？但只误了路啊。」行者道：「师父说那里话。常言道：『一日为师，终身为父。』
逐句解 Line by line
Tripitaka said, "I cannot even sit up now — how am I to mount the horse? It only means the journey is delayed."
得 is the unstressed de in a cannot-manage-it construction: rise and sit, and not get it done. The character before it is a plain verb, which is what settles the reading.
"But it only means the road is delayed."
啊 at the end is a sigh more than a word. Tripitaka's whole worry is the schedule, which is touching, since he is the one who cannot stand.
Pilgrim said, "What sort of talk is that, master?
那 is nǎ, the question word. 那裡話 is not a real question at all — it is a set rebuff, roughly where does talk like that come from, and it is still the ordinary Chinese way of telling someone kindly to stop being silly.
The common saying goes, 'One day a teacher, a father for life.'
Here is the famous one. 為 is wéi at both appearances, the copula to be, not the wèi of on account of. The proverb is still in daily use in Chinese and it means what it says: a teacher, however briefly, is owed the standing of a parent forever.
Pilgrim quotes a proverb about filial duty to explain why nobody is going anywhere, and the choice of proverb is the whole character sketch. This is the monkey who tore up heaven, who has been beaten and collared and sent away, and what he reaches for is the most conventional maxim in the Confucian household.
It is also, quietly, an argument about the relationship. Tripitaka is his teacher by a formality — the man pulled a rock off him and gave him a name. Pilgrim is choosing to treat that formality as blood.
And notice what it does to the schedule. Tripitaka frames his illness as a delay to the mission. Pilgrim answers by changing the frame entirely: there is no mission separate from the man. The road can wait.