Sharpening sheath adapted to receive a knife, and combination of such a sheath and a knife

A sheath, adapted to receive a knife to be sharpened or stored, comprising:

• a cavity for receiving a blade;
• an access opening at one end of the cavity;
• the sheath comprising in the vicinity of the access opening an upper part having a guiding device and a lower part configured to be applied to a cutting edge of the blade when inserted into or extracted from the sheath,
• wherein the guiding device comprises a V-shaped groove configured to receive a back of the blade;
• and
• wherein the lower part comprises two elongate elements arranged in a V-shape opposite the V-shaped groove of the guiding device and configured to sharpen the cutting edge of the blade, the two elongate elements and the V-shaped groove together delimit a diamond-shaped opening configured to receive an end of the blade when the knife is inserted and stored in the sheath, the lower part being mounted so as to be movable with respect to the guiding device, the lower part being biased towards the guiding device.