Spin here refers spinning yarn or spinning cotton.
Mnemonic
[f-] Frodo is in the [3] basement of the [-ang] chapel where he is 纺 spinning some 纟 silk. The 纟 silk he 纺 spins has a giant holy 方 compass depicted in the middle of it. Some priests stand by them with their own holy 方 compasses which all point to the recently 纺 spun纟 silk, indicating that it really is something holy. They all praise Frodo's 纺 spinning skill in the dark chapel basement.