Imam Sadiq (a) said:
“Here I give you three pieces of advice on forbearance and tolerance;
If someone tells you, “If you insult me with one word, I will reply with ten words!”
Tell him, “But if you insult me with ten words, you will not receive even one from me!”
And if he insults you, tell him: “If I deserve the insult you give, I ask God to forgive me, but if you lie, I ask God to forgive you!”
And whoever promised you harm, promise him support and care!
َSource:
Bihar al-Anwar, vol. 1, p. 224.