To rub wood or bamboo (in order to start a fire).
Two bamboo sticks or soft wooden ones are rubbed together until they get hot and ignite. Another way of getting sparks is to make a hole in a piece of board. Another piece of wood is inserted into the hole and made to rotate fast by means of an attached stick and string. Sparks or bits of the glowing stick will drop down onto very dry pieces of coconut husk or cotton prepared ahead of time underneath and start a fire.
Go and rub wood so that we will have fire.
They are rubbing wood (in order to start a fire).