Origen thought that the command not to have two coats was addressed to the Apostles because of what Jesus said in Matthew 10:10 about not taking two coats. The command is to share with him who has none. The alternate meaning is that no man can have two masters. We are not to be clothed with the garment of the old man, but with the new.
St Cyril of Alexandria comments that here St Luke has introduced three sets of people who ask John questions: the multitude; the tax collectors; and the soldiers. In the same way a skilful physician applies a fitting remedy to each ailment, so too does the Baptist give each group the right remedy: the multitudes must practice love as they strive for repentance; the tax collectors must be restrained in their collecting; and the soldiers should be content with their wages an oppress no one.
John knows he is not the promised Messiah, but knows, too, that he is at hand, because he knows that the one who is coming will baptise with the Spirit, which will demonstrate that he is Lord: only Christ can do this.
St Cyril of Jerusalem reminds us that John, filled with the Spirit from his mother’s womb, was sanctified for the purpose of baptising the Lord, but he knows that his is the lesser baptism and that when Jesus comes, he will decrease as Jesus must increase; he is humble and obedient and resists any temptation to vainglory.
St Ambrose wrote that 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 from the worthless, as if by a winnowing 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 the 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. He confers so 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 radiancy of goodness.