Wis 16:21

“For your substance, that is, your power of sustaining, and your sweetness, that is, your power of delighting, which you have toward your children, namely sustaining them through the substance of the food and delighting them through the taste of the same food, you showed etc.; in the Psalm: "You prepared in your sweetness for the poor, O God"; you showed, I say, by bestowing upon them the aforesaid food that sustains and delights. And serving, namely the aforesaid food or bread, the will of each one, namely of those eating, it was turned to what each one wished, that is, to whatever taste: for it had, as was said, one determined taste by nature, but various tastes by divine grace. Mystically, by the manna Christ was fittingly signified under the Sacrament of the altar, first because he himself is the bread of angels, namely of priests, according to that passage of Malachi 2: "He is the angel of the Lord of hosts." Second, because it is prepared from heaven, that is, because it is confected by heavenly power; John 6: "I am the living bread, who came down from heaven"; in the Psalm: "You prepared their food, for thus is its preparation." Third, because those eating from it according to their desire, that is, their devotion, are refreshed, according to that word of the Psalm: "You have granted him the desire of his soul"; likewise in the Psalm: "He brought them their desire, they were not defrauded of their desire." Fourth, because with it the dew of grace descends and is given, just as dew also descended with the manna, as is found in Numbers eleven. And therefore this bread is called eucharist: eucharist is interpreted as good grace. Fifth, because, just as the manna appeared like "white coriander seed," so also Christ is received under a white cloud: Apocalypse fourteen: "Behold, a white cloud, and upon the cloud one sitting like the Son of Man." Sixth, because it was gathered on six days and not on the Sabbath, so Christ is received under the Sacrament in the present, but in the future Sabbath, of which Isaiah sixty-six says: "There shall be Sabbath after Sabbath," He will be seen openly: First Corinthians thirteen: "But then face to face"; likewise First John three: "We shall see Him as He is." Seventh, because they were nourished by that food in the desert for forty years until the entrance into the promised land, so until the end of the world in the desert of this world the faithful of the Church are nourished, according to that word of Matthew twenty-eight: "Behold, I am with you all days even to the consummation of the age."”

“Therefore, the substance of the Father is designated as the Son by the prophetic oracles long ago, as Solomon says: For you showed your substance and sweetness, which you have for your sons (Wis. 16:21), which appeared to have flowed down to the people of Israel from heaven in the form and image of heavenly bread. The Lord Himself explained this in the Gospel, saying: Moses did not give you bread from heaven, but my Father gives you bread from heaven (Jn. 6:32); clearly designating Himself as the bread when He says: I am the living bread which came down from heaven (Ibid. 41). Of whom also the prophet David says: Man ate the bread of angels (Ps. 77:25). For in order to show even more clearly the unity of substance and equality of divinity between the Father and the Son, He Himself says in the Gospel: I am in the Father, and the Father is in me. And: I and the Father are one (Jn. 10:38, 30). This refers not only to the unity of will, but to one and the same substance.”

“Where they say that the Son was not born from the substance of the Father. But if they should say: the Son was not born from the paternal substance, but generated from another substance. Response. We also, who confess the Father and the Son to be of one substance, have taught by divine authority that the Son is from the substance of God the Father, as the prophet Jeremiah says: "Take up mourning over the minds, and lamentation over the paths of the desert, because they have failed, since they are not men; because they were unwilling to hear the voice of my substance, from the birds of the sky even to the beasts they have fallen away in mind" (Jer. 9:10). Likewise there: "Who has stood in the substance of the Lord, and will see the word of God? Who has given ear and heard" (Jer. 23:18)? And there: "If they had stood in my substance, and if they had heard my words, and if they had taught my people, I would have turned them away from their most evil pursuits" (Jer. 23:22). And the Apostle: "Who, being the radiance of glory and the form of his substance" (Heb. 1:3). Likewise he himself: "For we have become partakers of God; let us hold fast the beginning of his substance" (Heb. 3:14). And in Solomon: "My substance is my sweetness" (Wis. 16:21). From this, then, recognize that he who is called the substance of God the Father is not believed to be foreign to that same substance.”