kamer (Sufism Glossary)

Kamer (the moon) is the barzakh (intermediate) maqām (spiritual station) between the hilāl (crescent) and the badr (full moon). In the hilāl position, its light diminishes; in the badr position, it increases. Since sounds rise whenever the moon appears on either side, when its light is complete in the observer's eye, it is called badr. The moon has no other phase outside these two rulings. However, when the badr is concealed from sight by the daylight that veils it between the eye and the full moon, it is called mahk. The side of the moon facing the sun is badr, just as the side facing us is also badr. The side that the sun does not reveal and keeps hidden is mahk. Between these two positions, as much as the light appears on one face, it decreases on the other; accordingly, to the extent that one face is concealed, light appears on the other. This is due to the curvature of the orbit (the path of the celestial sphere). Therefore, it is never always in the badr or always in the mahk state. This occurs due to a secret that Allah wills. (Futūḥāt, III, 109)