Answer:
I'm the source of all emotion, but I'm caged in a white prison.
I'm tall in the morning and short in the noon. I disappear at night but I will be back soon.
I bind it and it walks. I loose it and it stops.
Scythe of darkness, Shadowโs light. Guiding eye of thirteenth sight.
As a whole, I am both safe and secure. Behead me, I become a place of meeting. Behead me again, I am the partner of ready. Restore me, I become the domain of beasts.
If itโs information you seek, come and see me. If itโs pairs of letters you need, I have consecutively three. What am I?