الكافي 2/1/139/16

16. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad ibn ‘Isa from abu Yahya al-Wasiti from certain individuals of our people from Abu ‘Abdillah عليه السلام who has said the following: “Statements are of three kinds: true, false and to establish truce among people.’ The narrator has said that it was asked of him, ‘May Allah keep my soul in service for your cause, what is establishing truce among people?’ The Imam said, ‘It is when you hear something about a man that, if he himself may hear it, his soul turns filthy (with anger) but when you meet him you say, ‘I heard so and so saying very good things about you, which is opposite of what you have actually heard about him.’”