Exodus 19

The Pentecost too we observe, that is, the fiftieth day from the passion and resurrection of the Lord, for on that day he sent to us the Holy Paraclete whom he had promised. This was prefigured in the Jewish Passover, for on the fiftieth day after the slaying of the lamb, Moses on the mount received the law written with the finger of God.

Against Faustus, a Manichaean 32.12

But the fifty-day period is also praised in Scripture, not only in the Gospel, because the Holy Spirit came on the fiftieth day, but even in the Old Testament. Therein fifty days are numbered from the celebration of the pasch by the killing of a lamb to the day on which the law was given on Mt. Sinai to the servant of God, Moses.

Letter 55

We come now to the desert, where the law was given, and this is what Scripture says: “But in the third month from when the people were brought out of Egypt.” The Lord spoke to Moses that those who were going to receive the law should purify themselves in readiness for the third day, on which the law was to be given. So at the beginning of the third month a purification is commanded in readiness for the third day.

Sermon 272B.6

Now when I go up eagerly into the mount—or, to use a truer expression, when I both eagerly long and at the same time am afraid (the one through my hope and the other through my weakness), to enter within the cloud and hold converse with God, for so God commands: If any be an Aaron, let him go up with me, and let him stand near, being ready, if it must be so, to remain outside the cloud.

Theological Oration 2:2

How indeed but in his body did Christ expiate the sins of the people? In what did he suffer, save in his body—even as we said: “Christ having suffered in the flesh”? In what is he a priest, save in that which he took unto himself the vocation of a priestly nation?

Exposition of the Christian Faith 3.11.86

The apostle Peter now rightly gives to the Gentiles this attestation of praise which formerly was given by Moses to the ancient people of God, because they believed in Christ, who like a cornerstone brought the Gentiles into that salvation which Israel had had for itself. He calls them “a chosen race” on account of their faith, that he may distinguish them from those who by rejecting the living stone have themselves become rejected. They are “a royal priesthood,” however, because they have been joined to his body who is their real king and true priest, who as king grants to his own a kingdom and as their high priest cleanses them of their sins by the sacrificial victim of his own blood. He names them “a royal priesthood” that they may remember both to hope for an eternal kingdom and always to offer to God the sacrifices of a stainless way of life.

Commentary on the Catholic Epistles, 1 Peter 2:9

The people then beheld the pillar of cloud, and it spoke to Moses. But who was the speaker? Obviously the pillar of cloud, which before appeared to the fathers in a corporeal form. And I have already shown that this was not directly and visibly the almighty God as such but the One whom we name as the Word of God, the Christ who was seen for the sake of the multitude of Moses and the people in a pillar of cloud, because it was not possible for them to see him like their fathers in human shape. For surely it was reserved for the perfect to be able to see beforehand his future incarnate appearance among men. And since it was impossible then for the whole people to bear it, he was seen now in fire in order to inspire fear and wonder, and now in a cloud, as it were in a shadowy and veiled form ruling them, as he was also seen by Moses for their sake.

Proof of the Gospel 5.14.241

However, even the people had to be purified two or three days beforehand, so as to come clean to the sacrifice, as we read in the Old Testament. They even used to wash their clothes. If such regard was paid in what was only the figure, how much ought it to be shown in the reality! Learn then, priest and Levite, what it means to wash your clothes. You must have a pure body wherewith to offer up the sacraments. If the people were forbidden to approach their victim unless they washed their clothes, do you, while foul in heart and body, dare to make supplication for others? Do you dare to make an offering for them?

On the Duties of the Clergy 1.50.258

In this wonderful agreement there is the very great difference, that in the Old Testament the people is held back by a fearful dread from approaching the place where the law was given; whereas in the New the Holy Spirit comes upon those who were assembled together waiting for his promised coming.

On the Spirit and the Letter 17.29

If ye endure chastening, God dealeth with you as with sons; for what son is he whom the father chasteneth not? But if ye be without chastisement, whereof all are partakers, then are ye bastards, and not sons. Furthermore we have had fathers of our flesh which corrected us, and we gave them reverence: shall we not much rather be in subjection unto the Father of spirits, and live? For they verily for a few days chastened us after their own pleasure; but he for our profit, that we might be partakers of his holiness. Now no chastening for the present seemeth to be joyous, but grievous: nevertheless afterward it yieldeth the peaceable fruit of righteousness unto them which are exercised thereby. Wherefore lift up the hands which hang down, and the feeble knees; And make straight paths for your feet, lest that which is lame be turned out of the way; but let it rather be healed. Follow peace with all men, and holiness, without which no man shall see the Lord: Looking diligently lest any man fail of the grace of God; lest any root of bitterness springing up trouble you, and thereby many be defiled; Lest there be any fornicator, or profane person, as Esau, who for one morsel of meat sold his birthright. For ye know how that afterward, when he would have inherited the blessing, he was rejected: for he found no place of repentance, though he sought it carefully with tears. For ye are not come unto the mount that might be touched, and that burned with fire, nor unto blackness, and darkness, and tempest, And the sound of a trumpet, and the voice of words; which voice they that heard intreated that the word should not be spoken to them any more: (For they could not endure that which was commanded, And if so much as a beast touch the mountain, it shall be stoned, or thrust through with a dart: [Exodus 19:13] And so terrible was the sight, that Moses said, I exceedingly fear and quake:) But ye are come unto mount Sion, and unto the city of the living God, the heavenly Jerusalem, and to an innumerable company of angels, To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect, And to Jesus the mediator of the new covenant, and to the blood of sprinkling, that speaketh better things than that of Abel. See that ye refuse not him that speaketh. For if they escaped not who refused him that spake on earth, much more shall not we escape, if we turn away from him that speaketh from heaven: Whose voice then shook the earth: but now he hath promised, saying, Yet once more I shake not the earth only, but also heaven. And this word, Yet once more, signifieth the removing of those things that are shaken, as of things that are made, that those things which cannot be shaken may remain. Wherefore we receiving a kingdom which cannot be moved, let us have grace, whereby we may serve God acceptably with reverence and godly fear: For our God is a consuming fire.

But if any is an evil and savage beast and altogether incapable of taking in the subject matter of contemplation and theology, let him not hurtfully and malignantly lurk in his den among the woods, to catch hold of some dogma or saying by a sudden spring and to tear sound doctrine to pieces by his misrepresentations. But let him stand yet afar off and withdraw from the mount, or he shall be stoned and crushed and shall perish miserably in his wickedness.

Theological Oration 2:2

The third day, however, is always applied to mysteries. For when the people had departed from Egypt, they offer sacrifice to God on the third day and are purified on the third day. And the third day is the day of the Lord’s resurrection. Many other mysteries also are anticipated in this day.

Homilies on Genesis 8:4

The law then was obviously given on the third day of the third month. Now count the days from the fourteenth of the first month, when the pasch was kept, to the third day of the third month. You will have seventeen of the first month, thirty of the second, three of the third, which makes fifty.

Letter 55

Again God produces the ordinary lightnings and thunders. But because they were done in an unusual manner on Mt. Sinai, and those voices were spoken there without a confused noise but in such a manner that it was evident from the most unmistakable proofs, … certain significant meanings were attached to them. Then they were miracles.

The Trinity 3.5.11

When Abraham offered his son Isaac, he was a type of God the Father, while Isaac prefigured our Lord and Savior. The fact that he arrived at the place of sacrifice on the third day is shown to represent the mystery of the Trinity. That the third day should be accepted in the sense of a promise or mystery of the Trinity is found frequently in the sacred books. In Exodus we read, “We will go a three days’ journey into the wilderness.” Again, upon arriving at Mt. Sinai it is said to the people, “Be sanctified, and be ready for the third day.” When Joshua was about to cross the Jordan, he admonished the people to be ready on the third day. Moreover, our Lord rose on the third day. We have mentioned all this because blessed Abraham on the third day came to the place which the Lord had shown him.

Sermon 84.2

But the sound of that voice and the corporeal appearance of the dove and the “parted tongues as it were of fire that sat upon every one of them,” like those terrible manifestations that happened on Mt. Sinai and that pillar of cloud by day and of fire by night, were performed and carried out as figurative acts. Now in these matters special care must be taken lest anyone believe that the nature of God, either the Father, the Son or the Holy Spirit, is subject to change or transformation. And let no one be troubled because sometimes the sign receives the name of the thing signified. Thus the Holy Spirit is said to have descended on Christ in the corporeal appearance, as it were, of a dove and to have remained upon him. Thus also the rock is called Christ because it signifies Christ.

Letter 169

What shall I say about this except that no one is so insane as to believe that the smoke, the fire, the cloud and the darkness and everything else of a similar nature are the substance of either the Word and the Wisdom of God which Christ is or of the Holy Spirit. For not even the Arians have dared to say this about God the Father. Therefore all those things were produced by a creature serving its Creator and were manifested by a suitable dispensation to the human senses.… Perhaps carnal thoughts will suggest that the cloud was certainly seen by the people but that within the cloud Moses saw the Son of God with his bodily eyes, whom the raving heretics will have to be seen in his own substance, because it was said, “Moses entered the cloud where God was.”

The Trinity 2.15.25

When about to give the law, the Lord descended in fire and smoke. Through the brilliance of his manifestation he enlightened the humble, and through the murky smoke of error he dimmed the eyes of the proud.

Commentary on Acts 2

But when she [the bride] has become worthy to have it said of her, as also it was said of Moses, that “Moses spoke, and God answered him,” then there is fulfilled in her that which he says: “Make me to hear your voice.” It is indeed high praise of her that is disclosed in that saying, “Sweet is your voice.” For thus also said the most wise prophet David: “Let my speech be sweet to him.” And the voice of the soul is sweet when it utters the word of God, when it expounds the faith and the doctrines of the truth, when it unfolds God’s dealings and his judgments.

Commentary on the Song of Songs 3.15

And this is pictured for you in the writings of Moses. For the God of all came down in the likeness of fire on Mt. Sinai, and there was a cloud, and darkness, and gloom and the voice of the trumpet with a loud ringing sound, according to the Scripture. The notes of the trumpet were, it says, few at first, but afterwards they waxed longer and became louder and louder continually. What then was it which the shadow of the law signified to us by these things? Was it not this: that at first there were but few to publish the gospel tidings; but afterwards they became many?

Homilies on the Gospel of Luke 60

Moses alone ascended to its very top, where the divine majesty shone forth in fire and a dark cloud. Only the more perfect know how to grasp and observe the deeper and most secret mysteries of the law; the carnal-minded people, content with the external aspects of the letter, and gathered apart, as it were, and below, stood to hear the words from heaven.

Homilies on the Gospels 11.17