1 It has been said on the sixth Psalm, that “the eighth” may be taken as the day of judgment. “For the eighth” may also be taken “for the eternal age;” for that after the time present, which is a cycle of seven days, it shall be given to the Saints.
2. “Save me, O Lord, for the holy has failed;” that is, is not found: as we speak when we say, Corn fails, or, Money fails. “For the truths have been minished from among the sons of men”. The truth is one, whereby holy souls are enlightened: but forasmuch as there are many souls, there may be said in them to be many truths: as in mirrors there are seen many reflections from one face.
3. “He has talked vanity each man to his neighbour”. By neighbour we must understand every man: for that there is no one with whom we should work evil; “and the love of our neighbour works no evil.” “Deceitful lips, with a heart and a heart they have spoken evil things.” The repetition, “with a heart and a heart,” signifies a double heart.
4. “May the Lord destroy all deceitful lips”. He says “all,” that no one may suppose himself excepted: as the Apostle says, “Upon every soul of man that does evil, of the Jew first, and of the Greek.” “The tongue speaking great things:” the proud tongue.
5. “Who have said, We will magnify our tongue, our lips are our own, who is Lord over us?”. Proud hypocrites are meant, putting confidence in their speech to deceive men, and not submitting themselves to God.
6. “Because of the wretchedness of the needy and the sighing of the poor, now I will arise, says the Lord”. For so the Lord Himself in the Gospel pitied His people, because they had no ruler, when they could well obey. Whence too it is said in the Gospel, “The harvest is plenteous, but the labourers are few.” But this must be taken as spoken in the person of God the Father, who, because of the needy and the poor, that is, who in need and poverty were lacking spiritual good things, vouchsafed to send His own Son. From thence begins His sermon on the mount to Matthew, where He says, “Blessed are the poor in spirit: for theirs is the kingdom of heaven.” “I will place in salvation.” He does not say what He would place: but, “in salvation,” must be understood as, in Christ; according to that, “For my eyes have seen Your salvation.” And hence He is understood to have placed in Him what appertains to the taking away the wretchedness of the needy, and the comforting the sighing of the poor. “I will deal confidently in Him:” according to that in the Gospel, “For He taught them as one having authority, and not as their scribes.”
7. “The words of the Lord” are “pure words”. This is in the person of the Prophet himself, “The words of the Lord” are “pure words.” He says “pure,” without the alloy of pretence. For many preach the truth impurely; for they sell it for the bribe of the advantages of this life. Of such the Apostle says, that they declared Christ not purely. “Silver tried by the fire for the earth.” These words of the Lord by means of tribulations approved to sinners. “Purified seven times:” by the fear of God, by godliness, by knowledge, by might, by counsel, by understanding, by wisdom. For seven steps also of beatitude there are, which the Lord goes over, according to Matthew, in the same sermon which He spoke on the Mount, “Blessed” are “the poor in spirit, blessed the meek, blessed they that mourn, blessed they which do hunger and thirst after righteousness, blessed the merciful, blessed the pure in heart, blessed the peacemakers.” Of which seven sentences, it may be observed how all that long sermon was spoken. For the eighth where it is said, “Blessed” are “they which suffer persecution for righteousness' sake,” denotes the fire itself, whereby the silver is proved seven times. And at the termination of this sermon it is said, “For He taught them as one having authority, and not as their scribes.” Which refers to that which is said in this Psalm, “I deal confidently in Him.”
8. “You, O Lord, shall preserve us, and keep us from this generation to eternity”: here as needy and poor, there as wealthy and rich.
9. “The ungodly walk in a circle round about”: that is, in the desire of things temporal, which revolves as a wheel in a repeated circle of seven days; and therefore they do not arrive at the eighth, that is, at eternity, for which this Psalm is entitled. So too it is said by Solomon, “For the wise king is the winnower of the ungodly, and he brings on them the wheel of the wicked.— After Your height You have multiplied the sons of men.” For there is in temporal things too a multiplication, which turns away from the unity of God. Hence “the corruptible body weighs down the soul, and the earthy tabernacle presses down the mind that muses upon many things.” But the righteous are multiplied “after the height of God,” when “they shall go from strength to strength.”
Source: The Enarrations, or Expositions, on the Psalms (New Advent)