Jeremiah 20:9

For they do not make their journey upon the royal highway as other men, but these giants select for themselves short-cuts, whereby gloriously they journey swiftly to the Heavenly mansions. For this hope so inflames them, as with fire, that they cannot rest from their incessant and headlong course on account of their joy. There comes to pass in them what was spoken by the blessed [Jeremiah], "I said, 'I shall not remember Him nor speak His name.' And there was in my heart as it were a flaming fire and it entered into my bones." Such is the recollection of God in the hearts of people who are drunk with hope on his promises.

And thus with greater ardour she raises herself to the very bosom of the Father, wherein is the Only-Begotten Son of God Who declares the secrets of God, which in the time to come are to be revealed face to face. But even now He discloses them partly and in a figure to those whom He deems worthy, and at the same time sheds forth from the Spirit and from His own countenance floods of resplendent light, so that he who is illuminated thereby may say, "But it was as a fire blazing in my bones and I am melted on all sides, and cannot stay." And David says, "Let my sentence come forth from Thy presence!"

Indeed, Christ, loving Moses, appeared to him in fire. And Jeremiah, having in himself the gift of divine love, said: "And there was a fire inflaming in my bones: and I was dissolved on every side, and I cannot bear it." Therefore, good charity having the wings of a burning fire, which flies through the chests and hearts of the saints, and consumes whatever is material and earthly: it tests whatever is sincere, and improves whatever it touches with its fire. This fire the Lord Jesus sent upon the earth, and faith shone forth, devotion was kindled, charity was illuminated, justice shone brightly. With this fire, he inflamed the hearts of his apostles, as Cleophas testifies, saying: Was not our heart burning within us, while he opened the Scriptures? Therefore, the flames of the Scriptures are divine. Indeed, the Scriptures were opening up, and the fire was coming forth, and it was penetrating the hearts of the listeners.