kieszeniami

In a sentence

• Chłopiec poszedł do domu z pełnymi kieszeniami.

  The boy went home with full pockets.

  In this sentence, 'kieszeniami' is in the instrumental case, used to describe the state or contents of the pockets that the boy has.

• Grałem w grę, gdzie ludzie ukradli skarby z kieszeniami smoka.

  I played a game where people stole treasures from the dragon's pockets.

  Here, 'kieszeniami' is used metaphorically to describe the 'pockets' belonging to a dragon, and it is once again in the instrumental case, indicating the relationship between the items and the described object.

• Dziecko bawi się zabawkami, chowając je do kieszeni matki.

  The child is playing with toys, hiding them into the mother's pockets.

  In this usage, 'kieszenie' refers to actual pockets belonging to the mother, showing ownership and usage of the noun in the locative sense to emphasize where objects are being placed.