Upon casting this spell for the first time, a transparent box appears in the caster's hands. This box is a 2ft cube with an open top. Anyone can place any items inside the box, the walls of the box are solid. Once cast, the box does not move.
As a cantrip, the caster can Fold the box. Doing so places a lid on the box and folds spacetime into a singular point anywhere within 5 ft of the caster. This point is smaller than the point of a pin. When the caster casts the cantrip, they can choose an object or spot for a point of reference. This point of reference can be anything: a specific spot on a wagon wheel, the tip of a feather in a hat, the heel of a boot, the 2nd knuckle of someone's right hand, etc. The folded box will always maintain its spatial relevance to that point of reference, if the point of reference moves, the fold moves in relation to it. As another cantrip, the caster can Unfold the box. Doing so moves the point to the caster's hands, expands the box to the original 2ft cube, and removes the lid.
When folded, the inside of the box acts as a pocket dimension where time is frozen. Objects inside the fold experience no movement and do not need air, food, or water. From the object's perspective: the lid of the box is put on and immediately removed. If the point that the box is folded to moved through any physical material, it cuts and burns through the material with no resistance.
When cast as a 4th level spell, the box gains 1ft in each dimension, making the box a 3x3x3ft cube. When cast as a 6th level spell, the box gains 2ft in each dimension, making the box a 4x4x4ft cube. When cast as an 8th level spell, the box gains 3ft in each dimension, making the box a 5x5x5ft cube.