Scabbards and sheaths are for the safe carry of an edged weapon to protect you and the edge from damage. This however is not the preferred long term storage method for any steel. Tight fitting scabbards are prone to trap moisture from the air and other sources. And leather is usually tanned with chemicals or lacquered to condition it; great for the leather but bad for your steel long term. If at all possible store your blades in a cool dry environment after cleaning and protecting them. Long term storage could mean months to years depending on the environment it’s kept in.
Finally exercise caution through this and all processes of blade care, the edge of your blade may be extremely sharp and could cause serious injury if used incorrectly. Make sure that the blade edge is never in a position where it could injure you or others. If at all possible never clean or oil the blade with the edge toward you. Avoid touching the edge at all times, our natural inclination is to test sharpness this way, but try to resist this urge and use paper or some other material that will prove to you it is still sharp. Always use discretion and common sense when working around others.