三清聖像 The Three Pure Ones
推開門，見有三清聖像，供桌有爐有香。即拈香注爐，禮拜三匝，方與道士行禮。遂至客位中，同徒弟們坐下。推开门，见有三清圣像，供桌有炉有香。即拈香注炉，礼拜三匝，方与道士行礼。遂至客位中，同徒弟们坐下。
逐句解 Line by line
They pushed the door open and saw the holy images of the Three Pure Ones, and on the altar table a censer and incense.
The 三清 are the highest gods of the Daoist pantheon — the Jade Pure, the Highest Pure and the Grand Pure — and three statues of them are what you would expect in the main hall of any working abbey, in the way a cross over the altar is what you expect in a church. 供桌 takes 供 as gòng, the offering sense: an altar table, not a supply table. And the door was shut a moment ago. It is open now because guests have arrived.
At once he took up incense, set it in the censer, made three circuits of obeisance, and only then exchanged bows with the Daoist.
拈 is to pick up between finger and thumb — the exact gesture for lifting a stick of incense. 三匝 is three circuits: he walks round, not merely bows three times. The word that carries the whole sentence is 方, only then — gods first, host second, and in that order. For a Buddhist monk to make full obeisance to the Daoist trinity is a generous piece of manners, and entirely in character.
Then he went through to the guest seats and sat down with his disciples.
客位 is the guest place — a distinct part of a Chinese hall, not just a chair. Where you are seated says what you are, and the four of them are being seated as guests. That matters, because a guest cannot refuse what he is offered without insulting his host, and the offering is about to start.
This is the most likeable thing Tripitaka does in the chapter, and it is the thing that finishes him. Shown into a rival religion's sanctuary, he goes straight to the altar, offers incense to gods that are not his, and circles three times before he so much as bows to the man standing next to him. Eight Rules had said outside that the robes differ and the practice is one. His master has just acted on it.
It is worth knowing how unusual that generosity is in period. Buddhists and Daoists had spent a thousand years arguing — over court patronage, over which founder had taught the other, over who got taxed. Anyone in a Ming audience would have felt the courtesy of that incense. It is also, in the plot's terms, the moment the pilgrims stop being travellers at a gate and become guests under an obligation.
The staging is doing the argument. Shut door, then open door; gods, then host; standing, then seated. Each step takes them further in and makes it harder to leave, and every one of them is initiated by Tripitaka himself out of pure good manners. Nobody has yet done anything to him at all.