Sheikh Tusi writes a man from among the Syrians visited Imam Mohammad Baqir (A.S.) and said, "Since you are a man of knowledge and learning your assembly is fruitful, valuable and worthy for me and so I attend your teaching session but I have enmity with you and your lineage." Imam did not reply him.
After a few days that man fell ill. Imam (A.S.) visited him along with his friends and sat by his bed, and enquired after his health. When the Syrian man saw this graciousness and magnanimity of the Imam he extremely repented about what he had said, and was ashamed. He did not know what response to give to the Imam (A.S.).
Imam (A.S.) gave orders about his food, treatment to his family members and prayed for him and got up. Not very long had passed that he got cured and left the ailment bed. Next day, he made it a point to reach the assembly of Imam (A.S.) and expressed repentance over what he had said and asked for apologies and became one of the permanent and everlasting friends of Imam (A.S.)
source : www.tebyan.net