Old man and his wise son

An old man had three sons.

He was on his death bed and wanted to leave all his property with his wisest son.
So he called all three of his sons and gave them equal amount of money.
He told them to buy something from that money that can fill their living room entirely.
The first son bought straw but due to shortage of money, he was not able to fill the entire room.
The second son bought sticks, but again they were not enough to fill the room.

But the third son bought two things that filled the room completely.

Can you find out what did he buy?

Answer:

The third son bought a candle and a matchstick with the money.
He lit the candle and the room was filled with light.