Stood and prayed thus with himself - Some have proposed to render this, “stood by himself” and prayed. In this way it would be characteristic of the sect of the Pharisees, who dreaded the contact of others as polluting, and who were disposed to say to all, Stand by yourselves. The Syraic so renders it, but it is doubtful whether the Greek will allow this construction. If not, it means, he said over to himself what he had done, and what was the ground on which he expected the favour of God.
God, I thank thee - There was still in the prayer of the Pharisee an “appearance” of real religion. He did not profess to claim that he had made himself better than others. He was willing to acknowledge that God had done it for him, and that he had a right to his gratitude for it. Hypocrites are often the most orthodox in opinion of any class of people. They know the truth, and admit it. They use it frequently in their prayers and conversation. They will even persecute those who happen to differ from them in opinion, and who may be really wrong. We are not to judge of the “piety” of people by the fact that they admit the truth, or even that they use it often in their prayers. It is, however, not wrong to thank God that he has kept us from the gross sins which other people commit; but it should not be done in an ostentatious manner, nor should it be done forgetting still that we are great sinners and need pardon. These were the faults of the Pharisees.
Extortioners - Rapacious; avaricious; who take away the goods of others by force and violence. It means, also, those who take advantage of the necessities of others, the poor and the oppressed, and extort their property.
Unjust - They who are not fair and honest in their dealings; who get the property of others by “fraud.” They are distinguished from “extortioners” because they who are unjust may have the “appearance” of honesty; in the other case there is not.