以答神功 Shrines to Answer Divine Merit
殿左邊立起四眾生祠，每年四時祭祀；又起蓋雷神、龍神等廟，以答神功。看畢，即命趲行。殿左边立起四众生祠，每年四时祭祀；又起盖雷神、龙神等庙，以答神功。看毕，即命趱行。
逐句解 Line by line
On the left of the main hall a living shrine to the four of them was set up, with sacrifices at the four seasons every year;
生祠, the living shrine, again — and it has actually been built. Four travelling monks now have a temple to themselves in a town they are about to leave, with a quarterly calendar of offerings.
and temples were also raised to the Thunder Gods and the Dragon Gods and the rest, to answer their divine merit.
以答神功 — to answer divine merit. The verb is the ordinary one for replying to a letter. The prefecture is settling its correspondence with heaven.
When they had finished looking, the order was given to hurry on.
趲 is to press on quickly — and it is the same verb the prefect used a moment ago for driving the builders. Four characters, and the pilgrims are leaving.
The shrines go up on both sides of the account: one for the four pilgrims, and others for the thunder and dragon gods who did the actual raining.
Pilgrim asked for exactly this when he sent the gods home — offerings from the households, thanksgiving at the festivals. The prefect has built it in stone within a fortnight, and Fengxian now has a standing relationship with the departments that supply its weather.
And then, in four characters, they go. The same word the prefect used for hurrying his builders is used for hurrying the pilgrims onto the road.