Winnows means to blow a current of air through (grain) in order to remove the chaff.
The poet says that the wind god winnows all the things of the house.
He crushes all the weak crumbling houses, doors, rafters, wood, bodies, lives and hearts.
The God does this to teach a lesson to all the bad people i.e. the people who do not respect the God of Wind.
Final Answer:
The poet says that the wind god winnows houses, doors, rafters, wood, bodies, lives and hearts.
