box
篋 centers on a container for storing or carrying items: a box, often one made of bamboo or used for documents.
篋 combines 竹 (bamboo) with 匧, which likely contributes the sound and the idea of a container. The character originally referred to a bamboo box.
The bamboo top 竹 covers a container shape 匧, like a bamboo box with a lid. Think of a traditional woven bamboo box for storing valuables.
For キョウ, imagine a box so tightly packed that it makes a 'kyo' sound when you try to close it: kyo -> キョウ, and the bamboo box resists.
Hōkyōin pagoda; pagoda containing a Hōkyōin sutra