Sayyiduna Ali (may Allah be pleased with him) said: When Sayyiduna al-Hasan was born, I named him Harb. The Messenger of Allah (peace and blessings be upon him) said to me: "What have you named him?" I said: Harb. He said: "No, rather name him Hasan." Then Sayyiduna al-Husayn was born, and I named him Harb. The Messenger of Allah (peace and blessings be upon him) said to me: "What have you named him?" I said: Harb. He said: "No, rather name him Husayn." Then another son was born, and I named him Harb. He (peace and blessings be upon him) said: "What have you named him?" I said: Harb. He said: "Name him Muhassin."
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 2763