The vengeful will face the Lord’s vengeance,
for he keeps a strict account of their sins.
Forgive your neighbor the wrong he has done,
and then your sins will be pardoned when you pray.
Does anyone harbor anger against a neighbor
and expect healing from the Lord?
If you have no mercy toward another like yourself
How can you seek pardon for your own sins?
If a mere mortal harbors wrath,
who will make an atoning sacrifice for his sins?
Remember the end of your life, and set enmity aside;
Remember corruption and death,
and be true to the commandments.
Remember corruption and death, and be true to the commandments. Remember the commandments, and do not be angry with your neighbor; remember the covenant of the Most High God, and overlook faults.
– Ben Sira 28:1-7
The King received the answer with great delight and looking at another said to the Sage, “What is the teaching of wisdom?” And the other replied, “Just as you would never want to experience anything evil, and would rather be a partaker of all good things, you ought to extend that same attitude toward your subjects and offenders. When criticizing them, do it mildly for God draws all men to Himself by his benignity.”
– The Letter of Aristeas 2:113
Moreover, it is ordained in the laws themselves that no one shall do to his neighbor what he would be unwilling to have done to himself.
– Philo, Hypothetica 7.6
Do not do unto others anything what you yourself dislike.
– Tobit 4:14:15
Hillel said: What is hateful to you, do not to your neighbor: that is the whole Torah, while the rest is the commentary thereof; now go and study it.
– BT Shabbat 30a
Do unto others as you would have them do unto you.
– Luke 6:31
Do to others whatever you would have them do to you.
This is the Law and the prophets.
– Matthew 7:12
Do not do what you yourself hate . . .
– Gospel of Thomas 6
R. Akiva said: “‘Love your neighbor as yourself’ (Lev. 19:18) is the great principle of the Torah.”
Ben Azzai differs: The verse, This is the book of the descendants of Adam . . . him whom God made in His likeness (Gen. 5:1) utters a principle even greater: you must not say, “Since I have been humiliated, let my fellow man also be humiliated; since I have been cursed, let my neighbor also be cursed.” For, as R. Tanhuma pointed out, “If you act thus, realize who it is that you are willing to have humiliated–” him whom God made in His likeness. 
– JT Nedarim 9:4, 41c; Genesis Rabbah 24:7