Church Fathers Commentary Luke 12:1-3

"In the mean time, when the many thousands of the multitude were gathered together, insomuch that they trod one upon another, he began to say unto his disciples first of all, Beware ye of the leaven of the Pharisees, which is hypocrisy. But there is nothing covered up, that shall not be revealed; and hid, that shall not be known. Wherefore whatsoever ye have said in the darkness shall be heard in the light; and what ye have spoken in the ear in the inner chambers shall be proclaimed upon the housetops." — Luke 12:1-3 (ASV)

Theophylact of Ohrid: The Pharisees indeed sought to trap Jesus in His words, so that they might lead the people away from Him. But this plan of theirs was reversed, for the people came to Him all the more. They gathered by the thousands and were so eager to follow Christ that they were stepping on one another. Truth is so mighty, and deceit is so feeble everywhere. This is why it is said that when a great multitude had gathered, so much that they were stepping on one another, He began to say to His disciples, Beware of the leaven of the Pharisees, which is hypocrisy.

St. Cyril of Alexandria: For they were false accusers; therefore Christ warned His disciples against them.

St. Gregory of Nazianzus: When leaven is praised, it is for composing the bread of life, but when it is blamed, it signifies a lasting and bitter maliciousness.

Theophylact of Ohrid: He calls their hypocrisy leaven because it perverts and corrupts the intentions of those in whom it arises. For nothing changes the characters of men as much as hypocrisy.

The Venerable Bede: For as a little leaven leavens a whole lump of dough, so hypocrisy will rob the mind of all the purity and integrity of its virtues.

St. Ambrose of Milan: Our Lord has introduced a very powerful argument for preserving simplicity and being zealous for the faith. We should not, in the manner of the faithless, practice one thing while pretending another in our words.

The argument is this: on the last day, our hidden thoughts—which accuse or else excuse one another—will be seen, revealing the secrets of our minds. This is why it is added, There is nothing hidden that will not be revealed.

Origen of Alexandria: He says this, then, either concerning the time when God will judge the secrets of men, or because no matter how much someone may try to hide another's good deeds by discrediting them, good, by its very nature, cannot be concealed.

St. John Chrysostom: It is as if He says to His disciples: "Although some now call you deceivers and sorcerers, time will reveal all things and convict them of slander, while making your virtue known. Therefore, whatever I have spoken to you in the small corner of Palestine, proclaim these things boldly to the whole world, with confidence and casting away all fear." And for this reason He adds, Whatever you have spoken in darkness will be heard in the light.

The Venerable Bede: Alternatively, He says this because all the things the Apostles spoke and suffered in the past, amid the darkness of oppression and the gloom of prison, are now publicly proclaimed, since the Church is known throughout the world and their acts are read.

The words, shall be proclaimed on the housetops, are spoken according to the custom in Palestine, where people were accustomed to live on flat rooftops. Their roofs were not pointed like ours, but were flat and level. Therefore, He says proclaimed on the housetops to mean spoken openly for all to hear.

Theophylact of Ohrid: Alternatively, this is addressed to the Pharisees, as if He were saying: "O Pharisees, what you have spoken in darkness—that is, all your efforts to tempt Me in the secrets of your hearts—will be heard in the light, for I am the light, and in My light whatever your darkness devises will be known. And what you have spoken in the ear and in private rooms—that is, whatever you have whispered into one another’s ears—will be proclaimed on the housetops, because it was as audible to Me as if it had been cried aloud from the rooftops."

In this you may also understand that the "light" is the Gospel, and the "housetop" represents the lofty souls of the Apostles. Thus, whatever the Pharisees plotted together was later revealed and heard in the light of the Gospel, with the great Herald, the Holy Spirit, presiding over the souls of the Apostles.