Bede : Some understand the murderer Cain as the Jews' lack of faith, the killing of Abel as the passion of the Lord and Savior, and the earth that opened its mouth and received Abel's blood from Cain's hand as the church (which received, in the mystery of its renewal, the blood of Christ poured out by the Jews). Undoubtedly those who have this understanding find water turned into wine, for they have a more sacred understanding of the saying of the sacred law. — Homilies on the Gospels 1.14 Bede : And Cain said to Abel his brother: Let us go out into the field. And when they were in the field, Cain rose up against Abel his brother, and killed him. And here the treachery of Cain and the innocence of Abel are both demonstrated: the innocence of Abel indeed, in that he simply followed his elder brother as a brother, being commanded, though his brother was inflamed with hostile hatred towards him; the treachery of Cain, in that he leads his brother outside to kill him, as if he could avoid divine presence in a more secret place: not considering, nor understanding that He who knew the secret things of his heart which reproved him, could also see wherever he withdrew and whatever he did in secret. — Commentary on Genesis (Hexaemeron) Bede : Cain led his brother out into the field and killed him. The Jewish people led the Lord out of their city Jerusalem and crucified Him at Calvary; from both instances of this ordeal we are reminded typically to go out to the Lord outside the camp, bearing His reproach, that is, leaving behind the fellowship of the world and the company of the wicked, we should willingly endure all worldly contempt for the love of our heavenly homeland. When the Lord asked Cain where his brother Abel was, he replied that he did not know, and that it was not his duty to be his brother's keeper. Even to this day, when the faithful, the members of Christ, inquire of the Jews about Christ, they say they do not know. They would themselves have been keepers of Christ if they had been willing to receive and uphold the Christian faith. For whoever keeps Christ in their heart does not say, like Cain, that they do not know their brother, or that they are not their brother's keeper. — Commentary on Genesis (Hexaemeron) Jerome : (Verse 8) And Cain said to his brother Abel. It is understood what the Lord said. Therefore, it is superfluous, what is found in the Samaritan and our volume, Let us go to the field. — Hebrew Questions on Genesis Philoxenus of Mabbug : And moreover we may see the cunning of Cain from the outlet which he found for his wickedness, for when he meditated slaying Abel his brother, and was not able to do it because he was near unto his parents, he said "Let us go down into the plain;" and Abel, in his innocency, heard and was persuaded like a child. And his simplicity imagined not wickedness, and he did not consider in his heart why Cain called him to the plain, neither did he perceive Cain's hatred towards him, because simplicity knoweth not how to be a spectator of these things; but in the innocency of his heart and in brotherly love towards him he turned, and whithersoever he called him he went readily and obediently. And observe here also the works of simplicity, and have regard unto the injurious effects of cunning and wickedness, and be strenuous to be on the side of the simple, who have at all times pleased God; and reject cunning as something which is unfit for thee, and which is not meet for the discipleship in which thou standest. — 13 Ascetic Discourses, Discourse 4 -- On Faith: First Discourse on Simplicity Philoxenus of Mabbug : Now this is the first lust which conquered the world, and because of it the first transgression of the law took place; and next Cain also, in turning unto this, meditated the killing of his brother that he might inherit the earth by himself. — 13 Ascetic Discourses, Discourse 11 -- On Abstinence Symeon the New Theologian : Why did Cain become a fratricide? Was it not by his evil will? He preferred himself to his Creator and followed after evil thoughts and so became abandoned to envy and committed murder. — DISCOURSES 4.2