Spin here refers spinning yarn or spinning cotton.
Mnemonic
[f-] Frodo is in the [3] basement of the [-ang] chapel where he is 紡 spinning some 糸 silk. The 糸 silk he 紡 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 紡 spun糸 silk, indicating that it really is something holy. They all praise Frodo's 紡 spinning skill in the dark chapel basement.