Matthew 7:12
7 “Ask and it will be given to you; seek and you will find; knock and the door will be opened for you. 8 For everyone who asks receives, and the one who seeks finds, and to the one who knocks, the door will be opened. 9 Is there anyone among you who, if his son asks for bread, will give him a stone? 10 Or if he asks for a fish, will give him a snake? 11 If you then, although you are evil, know how to give good gifts to your children, how much more will your Father in heaven give good gifts to those who ask him! 12 In everything, treat others as you would want them to treat you, for this fulfills the law and the prophets.
Didache 1:2
1 There are two Ways: one of Life and one of Death, and there is a significant difference between the two Ways. 2 The way of life is as follows: First, you should love the God who created you; secondly, love your neighbor as yourself. Treat others as you would want to be treated. 3 Now, the teaching behind these words is this: Bless those who curse you, pray for your enemies, and fast for those who persecute you. What credit is it to you if you love only those who love you back? Don't even the non-believers do the same? Instead, love those who hate you, and you will have no enemies. 4 Refrain from indulging in carnal and bodily desires. If someone strikes you on the right cheek, turn to them the other cheek also, and you will be perfect. If someone compels you to go one mile, go two. If someone takes your coat, offer them your shirt as well. If someone takes from you what belongs to you, do not refuse, even if you can.
Notes and References
"... If the Didachist did not employ a non-canonical source as he composed the whole of chapters 1–5, his second verse may still present a challenge to that general conclusion. There one encounters what has often been called the “Negative Golden Rule.” Didache 1:2 states, “[A]s many [things] as you might wish not to happen to you, likewise, do not do to another.” This is certainly similar to Jesus’ statement in Matthew 7:12, where it is expressed positively. A pre-Christian history to this piece of ethical advice exists, however. Tobit’s advice to his son in 4:15 is similar: “And what you hate, do not do to anyone.” Furthermore, the famous dictum of Hillel to the inquiring Gentile in Babylonian Shabbat 31a also sounds very similar to Didache 1:2. Did the Didachist deliberately alter the Dominical saying in accord with Jewish tradition, or could this be an example of a genuine agraphon - an unwritten saying of Jesus? No one knows, but anyone should recognize this as a further example of the definitely Jewish character of the Didache, even in its Christian dress ..."
Varner, William The Didache's Use of the Old and New Testament (pp. 127-151) The Master's Seminary Journal 16/1, 2005