Clement of Rome

Every kind of honour and happiness was bestowed upon you, and then was fulfilled that which is written, "My beloved ate and drank, and was enlarged and became fat, and kicked." [Deuteronomy 32:15] Hence flowed emulation and envy, strife and sedition, persecution and disorder, war and captivity. So the worthless rose up against the honoured, those of no reputation against such as were renowned, the foolish against the wise, the young against those advanced in years. …

Clement's First Letter to the Corinthians, Chapters 3-4 ↗

Augustine of Hippo

[The pagans say:] "They find fault with the sacred ceremonies, the sacrificial victims, the burning of incense, and all the other parts of worship in our temples; and yet the same kind of worship had its origin in antiquity with themselves, or from the God whom they worship, for He is represented by them as having been in need of the first-fruits." This question is obviously founded upon the passage in our Scriptures in which it is written that Cain brought to God a gift from the fruits of the earth, but Abel brought a gift from the …

Letters 102.3 ↗

Bede

It came to pass after many days that Cain brought an offering to the Lord of the fruit of the ground: Abel also brought of the firstlings of his flock and of the fat thereof. It is clearly shown that both brothers had faith in God, both either naturally admonished or taught by their parents, knew that gifts should be offered to God, and that the guilt of their father's transgression should be washed away by sacrifices offered to Him: but because they did not offer with an equal mind, their offerings were not equally accepted. …

Commentary on Genesis (Hexaemeron) ↗