Jesus makes our hearts burn
Origen, 3d c. AD:
Homily on Exodus, 12, 4
This shows that we must not only employ zeal to learn the sacred literature but also pray to the Lord and entreat "day and night" that the lamb "of the tribe of Judah" may come and, himself taking "the sealed book", may deign to open it. For it is he who "opening the Scriptures" kindles the hearts of the disciples so that they say, "Did not our hearts burn within us while he opened to us the scriptures?"
Even here fire is double. There is a certain fire in this age and there is fire in the future . The Lord Jesus says, "I came to cast fire on the earth." That fire enlightens. Again the same Lord says in the future to the "workers of iniquity": "Go into everlasting fire which my Father has prepared for the devil and his angels." That fire burns. Nevertheless, that fire which Jesus came to cast "enlightens," indeed, "every man coming into this world." But it has something also which burns, as those acknowledge who say, "Was not our heart burning within us when he opened to us the Scriptures?" Therefore, "by opening the Scriptures" he both burned and enlightened at the same time. I do not know, however, whether that fire in the world to come which burns also has power to enlighten.
(Translated by R. Heine)
Homily on Leviticus 9,9
Do you want me to show you how the fire goes out from the words of the Holy Spirit and ignites the hearts of believers? Hear David speaking in the Psalm: "The declaration of the Lord has set him on fire." And again in the Gospel it was written, after the Lord spoke to Cleopas, "Was not our heart burning within us when he opened the Scriptures to us?” Whence will you burn? Whence will "the coals of fire" be found in you who are never set on fire by the declaration of the Lord, never inflamed by the words of the Holy Spirit? Hear also in another place David himself saying "My heart burned within me and in my meditation fire became inflamed." From where do you glow? Whence is the fire kindled in you who never meditate on the divine declarations? On the contrary, what is more unfortunate is that you glow in the spectacles of the circus, in the contests of horses, in the contest of athletes. And so this fire is not from the altar of the Lord, but it is that which is called "an alien fire" and you heard a little earlier that those who brought "a foreign fire before the Lord were destroyed." You also burn when wrath fills you and when rage inflames you; meantime you burn also with the love of the flesh and you are cast away into the fires of most disgraceful passions. But all this is "an alien fire" and contrary to God, which, without a doubt, whoever bums will endure the lot of Nadab and Abiud.
(Translated by G. W. Barkley )
Homily on Joshua, 15, 3
Moreover, Scripture also mentions the horses of the Egyptians, even those very ones ordered to be destroyed at that time. From this, we understand that, in the figure of asses, the nations that come to an easy faith are deservedly preserved. In the figure of horses and chariots, however, the demons who are adversaries and enemies to human salvation, are justly destroyed. If we understand the horses that are commanded by the precept of God to be hamstrung, together with their chariots, as the passions of the body - that is, lust, petulance or pride, and fickleness, by whom the unhappy soul, just as a rider, is borne and carried to great dangers - this understanding will not be contrary to our reasoning. The horse, of course, is hamstrung when the body is humbled by fastings and vigils and by every pain of self-denial. And the chariots are consumed by fire when the word of the Lord is fulfilled in us, as he says, "I came to send fire on the earth, and how I wish that it be set ablaze!" Those persons already revealed themselves to burn in that fire who said, "Was not our heart burning within us when he opened the Scripture for us?"
(Translated by Barbara Bruce)
Homily on Jeremiah, 20, 8
The pain from the fire which Jeremiah has described is of a different sort; he says, "And it arose in my heart as a burning fire, flaming in my bones, and it spread everywhere and I could not bear it". That is the fire the Savior kindles when he says, "I came to cast fire on the earth", and since the Savior kindles that fire, therefore he begins by a fire in those who begin to hear him and he first casts fire upon their heart. This is what Simon and Cleopas confess when they speak about his words: "Were not our hearts burning on the way while he opened up the Scriptures to us?" Hence, the hearts of Simon and Cleopas burn with fire. Hear them speaking: "Were not our hearts burning?"
(translated by J. C. Smith)
Commentary on the Gospel of John, Book 1, 49-50
Paul says: "I will know not the word that is puffed up, but the power; for the kingdom of God is not in word but in power." (1 Corinthians 4:19, 20) And in another passage: "And my word and my preaching were not persuasive words of wisdom, but in demonstration of the spirit and of power" (1 Corinthians 2:4). To this power Simon and Cleophas bear witness when they say: "Was not our heart burning within us by the way, as he opened to us the Scriptures?"
St. Ambrose, Isaac, or the Soul, 8.77, written ca. 390
Also, "zeal is like the nether world", because one who has zeal for God for Christ’s sake is not sparing of what is his own. And so love encompasses death and love encompasses zeal and love possesses wings of fire. Indeed, Christ, loving Moses, appeared to him in fire, and Jeremiah, having in himself the gift of divine love, said, 'There was a burning fire in my bones and I have become weakened on every side and I cannot bear it." Good then is love, having wings of burning fire, that flies through the breasts and hearts of the saints and consumes whatever is material and earthly but tests whatever is pure and with its fire makes better whatever it has touched. This fire the Lord Jesus sent upon earth, and faith shone bright, devotion was enkindled, love was illuminated, and justice was resplendent. With this fire He inflamed the heart of His Apostles, as Cleophas bears witness, saying, "Was not our heart burning within us, while he was explaining the scriptures?" Therefore the wings of fire are the flames of the divine Scripture.
Guigo II the Carthusian, The 6th Letter on the Contemplative Life, 142-150, written in the late 12th c.
I sought your face, Lord, Lord, I sought your face. I have long pondered in my heart and a fire has grown immensely in my meditation, the desire to know you better. When you break for me the bread of the Holy Scripture, you become known to me in this breaking of bread; the more I know you, the more I wish to know you, not only in the bark of the letter, but in the taste of the experienced knowledge. And I do not ask this gift, Lord, because of my merits, but because of your mercy.
Thomas à Kempis, Imitation of Christ, Book 4, ch. 14, early 15th c.
For they verily know their Lord in the breaking of bread, whose heart so ardently burns within them when Jesus walks with them by the way. Ah me! Far from me for the most part is such love and devotion as this, such vehement love and ardor. Be merciful unto me, O Jesus, good, sweet, and kind, and grant unto Thy poor suppliant to feel sometimes, in Holy Communion, though it be but a little, the cordial affection of Thy love, that my faith may grow stronger, my hope in Thy goodness increase, and my charity, once kindled within me by the tasting of the heavenly manna, may never fail. But Thy mercy is able even to grant me the grace which I long for, and to visit me most tenderly with the spirit of fervor when the day of Thy good pleasure shall come. (Translated by William Benham)
St. John of the Cross, The Ascent of Mount Carmel, part 6, chapter 31 (1581-1585)
Where signs and witnesses abound, there is less merit in believing. In this way Saint Gregory says that faith has no merit when human reason provides experience. And thus these marvels are never worked by God save when they are really necessary for belief. Therefore, to the end that His disciples should not be without merit, though they had experience of His resurrection, He did many things before He showed Himself to them, so that they should believe Him without seeing Him. To Mary Magdalene, first of all, He showed the empty tomb, and afterwards bade the angels speak to her (for, as Saint Paul says, faith comes by hearing); so that, having heard, she should believe before she saw… And He first sent to tell His disciples, with the women, and afterwards they went to see the tomb. And, as to those who went to Emmaus, He first of all enkindled their hearts in faith so that they might see Him, dissembling with them as He walked.
St. Francis of Sales, Treatise of the love of God, book 3, ch. 9, written in 1615
"How sweet are thy words, O Lord, to my palate, said that great king, more than honey to my mouth?" (Ps. 118, 103). "Was not our heart burning within us, whilst he spoke in the way?" said those happy pilgrims of Emmaus, speaking of the flames of love with which they were touched by the word of faith. But if divine truths be so sweet, when proposed in the obscure light of faith, O God, what shall they be when we shall contemplate them in the light of the noonday of glory!