Whose fan is in his hand, and he will thoroughly purge his floor, and will gather the wheat into his barn; but the chaff he will burn with fire unquenchable.
All Commentaries on Luke 3:17 Go To Luke 3
Ambrose of Milan
AD 397
Through the sign of the fan, the Lord is said to have the right to distinguish merits. When the grain is winnowed on the threshing floor, the full grain is separated from the empty, the fruitful is separated from the worthless, as if by a weighing of a blowing breeze. So through this comparison, the Lord is manifest, because on the day of judgment, he separates the merits and fruits of solid virtue from the unfruitful shallowness of worthless ostentation and inadequate deeds, before he establishes the people of perfect merit in a heavenly home. For he who has deserved to be like him is the perfect fruit. The Lord is like the grain of wheat that has died. So he confers very many fruits on us, hated by chaff and no friend to worthless merits. And therefore, a fire that is not harmful by its nature will burn before him. For he who burns up the evils of wickedness adds to the radiance of goodness.