Ps 42:3

“But in order that she may do this, hear what she says, what she supplicates, what she prays for. Pray thou for what thou hearest; pray for it when thou hearest it; let these words be the voice of us all: "O send out Thy Light and Thy Truth. They have led me, and brought me on unto Thy holy hill, and into Thy Tabernacles." For that very "Light" and "Truth" are indeed two in name; the reality expressed is but One. For what else is the "Light" of God, except the "Truth" of God? Or what else is the "Truth" of God, except the "Light" of God? And the one Person of Christ is both of these. "I am the Light of the world: he that believeth on Me, shall not walk in darkness." "I am the Way, the Truth, and the Life." He is Himself "the Light:" He is Himself "the Truth." Let Him come then and rescue us, and "separate at once our cause from the ungodly nation; let Him deliver us from the deceitful and unjust man," let him separate the wheat from the tares, for at the time of harvest He will Himself send His Angels, that they may "gather out of His kingdom all things that offend," and cast them into flaming fire, while they gather together the corn into the garner. He will send out His "Light," and His "Truth;" for that they have already "brought us and led us to His holy hill, and into His Tabernacles." We possess the "earnest;" we hope for the prize. "His holy Hill" is His holy Church. It is that mountain which, according to Daniel's vision, grew from a very small "stone," till it crushed the kingdoms of the earth; and grew to such a size, that it "filled the face of the earth." This is the "hill," from which he tells us that his prayer was heard, who says, "I cried unto the Lord with my voice, and He heard me out of His holy hill." Let no one of those that are without that mountain, hope to be heard unto eternal life. For many are heard in their prayers for many things. Let them not congratulate themselves on being heard; the devils were heard in their prayer, that they might be sent into the swine. Let us desire to be heard unto eternal life, by reason of our longing, through which we say, "Send out Thy Light and Thy Truth." That is a "Light" which requires the eye of the heart. For "Blessed" (He saith) "are the pure in heart, for they shall see God." We are now on His Hill, that is, in His Church, and in His Tabernacle. The "tabernacle" is for persons sojourning; the house, for those dwelling in one community. The tabernacle is also for those who are both from home, and also in a state of warfare. When thou hearest of a tabernacle, form a notion of a war; guard against an enemy. But what shall the house be? "Blessed are they that dwell in Thine house: they will be alway praising Thee."”

“The beam that emanates from light does not come after the light. True light never lacks a beam, having it as part of its substance to shine, just as it always has it as part of its substance to exist. But the manifestation of this beam has been called a "sending," by which Christ appeared to the world. Although he filled all things with his invisible majesty, he came, nevertheless, to those who had not known him, as if from a very remote and deep seclusion. At that time, he took away the blindness of ignorance, as it has been written: "For those sitting in darkness and in the shadow of death, a light has risen." Of course the light of truth has been sent out in prior ages to enlighten the holy fathers and prophets, as when David said, "Send out your light and your truth." Of course the divinity of the Son has made clear the works of his presence "in various ways and by many signs." Yet all these prefigurations and all these miracles bore testimony about that "sending" of which the apostle speaks: "When the fullness of time came, God sent his Son, made from a woman, made under the Law."”

“"Send forth." Here he sets forth advancement in good. And first he asks for the divine goods by which he is advanced; second, he asks for the advancement itself. He asks for two goods: light and truth. One arrives at God by steps of the mind and through knowledge. Heb. 4: "Entry is promised to those who believe." Two things are necessary for knowledge: namely, light and the object known. Eph. 5: "All that is made manifest is light." And so he asks for two things: namely, light and truth, to which I cannot attain by myself. And so he says, "send forth your light and your truth." Light and truth are the same thing here, because they are understood as referring to Christ. "Send forth your light," that is, Christ. Jn. 1: "He was the true light," etc. "And your truth," because Christ Himself is truth. Jn. 14: "I am the way, the truth, and the life." As if to say: God the Father, send forth Christ. Or light here is understood as the law, because Prov. 6: "The commandment of the Lord is a lamp, and the law is light." "And your truth," that is, the New Testament. Then the advancement in good is set forth. And he sets forth, first, the direction in approaching, at "they themselves have led me," namely, the light and the truth have led me to you. Or "they have led me," that is, they have drawn me away from evils and "have brought me to your holy mountain and into your tabernacles." This prayer corresponds to the desire of the preceding Psalm: "I shall pass over into the place," etc. And because this does not yet suffice, I ask to be brought by God to the mountain, etc. Jerusalem was at the foot of the mountain on the north side. And thus those who went there first arrived at the mountain. Second, they went to the dwelling place. Third, to the place of sacrifice, namely the altar. And even there my spirit does not rest, but ascends to God; and so he says, "they have brought me to your holy mountain and into your tabernacles," that is, to the dwelling place. And again the spirit does not rest there, but goes to the house of God, that is, to the altar. And so he says, "I will go in to the altar of God." And the spirit does not rest there either, lest it seem to be an idolater, but goes to God, "who gives joy to my youth." Mystically, however, by the mountain and the tabernacle the present Church is designated, or the heavenly Church. As if to say: they have led me into your Church. Is. 2: "The mountain of the house of the Lord shall be prepared on the top of the mountains," etc. And "tabernacles," that is, the diverse communities of saints, which are a kind of pilgrimages upon the earth; Heb. 11. And this Church is called the gate of heaven. Gen. 28: "This is no other but the house of God and the gate of heaven." And so it is also called the altar of God, that is, God Himself. Rev. 21: "God Himself is the temple," because all spiritual sacrifices are to be offered in God, not in any earthly thing. And there shall be joy. Is. 66: "You shall see, and your heart shall rejoice." Mt. 25: "Enter into the joy of your Lord." And so he says, "who gives joy to my youth," that is, there shall be renewal and youth, because, as is said in Eph. 4, "we shall all appear in the measure of the age of the fullness of Christ." And so he says "youth." Ps. 102: "Your youth shall be renewed like the eagle's." And priests say this Psalm when they approach the altar, because these two things, namely joy and renewal, are necessary for those who wish to approach the heavenly altar. Lev. 10: "How could he eat or please the Lord in sacred ceremonies with a sorrowful mind?" Likewise, there is no oldness of sin there. 1 Jn. 2: "I write to you, young men." Or everything that has been said refers to the heavenly homeland, in which we ought to stand in desire and toward which we ought to proceed with longing. And this is what he designates when he says, "to your holy mountain." Ex. 15: "You shall bring them in and plant them on the mountain of your inheritance," because there is stability of state there. Likewise, there is the fellowship of saints; hence he says, "and into your tabernacles." Num. 24: "How beautiful are your tabernacles, O Jacob," etc. Ps. 83: "How lovely are your tabernacles, O Lord of hosts." And they are called tabernacles because, although men are citizens by grace, nevertheless according to the condition of human nature they are guests there. Third, the altar designates the humanity of Christ. Is. 33: "They shall see the king in his beauty." And Christ is called the altar of God. Heb. 13: "We have an altar, from which they who serve the tabernacle have no power to eat." Because just as all carnal sacrifices were offered on the altar, so all prayers are offered through Christ. Hence every prayer ends with: "through Christ our Lord." But because there is no rest in His humanity, the soul reaches further to His divinity; hence he says, "to God," etc. Job 22: "You shall abound in delights from the Almighty, and you shall lift up your face to God." The effect of the prayer is the confession of praise; hence he says: "I will praise you upon the harp, O God." And he says this on account of the affection, because Is. 51: "Joy and gladness shall be found in her." And he says "upon the harp," to distinguish it from the psaltery; because the psaltery sounds from above, but the harp from below. Hence, "I will praise upon the harp," because we have been delivered from the evils of the world. And upon the psaltery, because we have obtained those joys from above.”

“Light, your Messias, as the Jews confess, (Jarchi) truth, the holy Spirit. (St. Chrysostom) — Both the titles may be applied to our Saviour. (Berthier) (St. Jerome) — We are in the utmost distress; be pleased to send us relief. (Calmet) — As thou hast sent Christ into the world to impart these graces, grant that we may know, and comply with our duties, before we approach to thy holy altar. — Holy hill, the Church, (Worthington) or tabernacle on Sion, where the Jews wished to be present. (Calmet)”