How to handle Pebbles?

The boy had been crying with hunger for past 1hr. His mom asked him for “10min” (to boil the food). She gave him a pebble to play. Boy played with that pebble and finally slept without eating, but he liked the pebble very much (as a toy).

The mom cursed the pebbles.

“Is it the mistake of pebbles if water is not able to boil them?”