The Epistle of Barnabas
Barnabae epistula
Barnabas. The Apostolic Fathers with an English Translation In Two Volumes. Vol. I. Lake, Kirsopp, translator. Cambridge, MA: Harvard University Press; London: William Heinemann Ltd. 1912.
And again he says to them, Did I command your fathers when they came out of the land of Egypt to offer me burnt offerings and sacrifices?
Nay, but rather did I command them this: Let none of you cherish any evil in his heart against his neighbour, and love not a false oath.