藏風聚氣 A Grave on the Sunny Slope
那獃子不嫌穢污，把個頭抱在懷裡，跑上山崖向陽處，尋了個藏風聚氣的所在，取釘鈀築了一個坑，把頭埋了，又築起一個墳塚。那呆子不嫌秽污，把个头抱在怀里，跑上山崖向阳处，寻了个藏风聚气的所在，取钉钯筑了一个坑，把头埋了，又筑起一个坟冢。
逐句解 Line by line
The Idiot, not minding the filth of it, took the head up in his arms, ran up the mountain cliff to a spot facing the sun, sought out a place that hoarded the wind and gathered the breath, took his rake and dug a pit, buried the head, and raised a grave mound over it.
藏風聚氣 comes back word for word from the description of the fiend's cave, and this is the only place in the chapter it occurs twice — there it certified a cannibal's lair, here it is Bajie choosing his teacher a decent plot. The phrase belongs to the practice of siting graves and houses, so this is its home use and the earlier one was the joke. 向陽, facing the sun, is the other standard requirement, and he gets that right too.
Fifty characters, one sentence, no dialogue, and it is the most affecting thing Bajie does in the book. He carries the head himself, uphill, without complaining about the mess, and then applies every rule he knows.
The phrase about hoarding wind and gathering breath is the chapter turning its own joke over. A few passages back it praised a cave where people were eaten. Here it is a fat, greedy, cowardly pig choosing his master a grave with good siting, and meaning every word of it.