Surah bint Mishrah narrated: I was among the women who were present with Sayyidah Fatimah (may Allah be pleased with her) when her labour pains began. The Prophet (peace and blessings be upon him) came to us and said: "How is she?" I said: O Messenger of Allah, she is in severe pain. He (peace and blessings be upon him) said: "When she gives birth, do not do anything to him before me." She said: Then she gave birth, and we cut his umbilical cord and wrapped him in a yellow cloth. Then the Messenger of Allah (peace and blessings be upon him) came and said: "What happened?" I said: She has given birth to a boy, and I have cut his umbilical cord and wrapped him in a cloth. He (peace and blessings be upon him) said: "You have disobeyed me." I said: I seek refuge in Allah from disobeying Allah and from the anger of His Messenger. He (peace and blessings be upon him) said: "Bring him to me." So I brought him to him, and he (peace and blessings be upon him) removed the yellow cloth and wrapped him in a white cloth, put his saliva into his mouth and did tahnik for him with his saliva. Then Sayyiduna Ali (may Allah be pleased with him) came, and he (peace and blessings be upon him) said: "O Ali, what have you named him?" He said: O Messenger of Allah, I have named him Ja'far. He (peace and blessings be upon him) said: "No, rather his name is Hasan, and after him will be Husayn, and you are Abu Hasan al-Khayr (the father of Hasan, the good)."
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 2529