An old man decided to give all his life savings | with ANSWER

An old man decided to give all his life savings to one of his 3 sons,
but he didn't know which one.
So he gave each of them 1 coin to buy something that must fill the whole room.
The oldest bought cotton but it was too small to fill the whole room,
the middle son bought hay but it still was too small
but the youngest one bought 2 things that filled the whole room
and immediately he got him his father's money.
What were the 2 items?



ANSWER

Candle and Matchstick. (The candle light filled the whole room)