An Enchanted Bottle
This ornate, ceramic flask is imbued with useful magics.
When corked, this bottle fills with cool, fresh water. Every day, it can create about two gallons of water before it runs dry, enough to keep one person well hydrated in the desert or to sustain two.
Once per day, the user may speak a command word and take a drink of water imbued with holy magic, granting a +1 competence bonus on a single attack roll, saving throw, or skill check made within one minute, as per a guidance spell. The user must choose to use the bonus before making the roll to which it applies.