Bishr bin Ghalib (may Allah have mercy on him) said: I was with Sayyiduna Abu Hurayrah (may Allah be pleased with him), and he saw Sayyiduna al-Husayn bin Ali (may Allah be pleased with them both) and said: O Abu Abdullah! I saw you on the hands of the Messenger of Allah (peace and blessings be upon him), which you had stained with blood, when you were brought to him at your birth. He (peace and blessings be upon him) cut your navel cord and wrapped you in a piece of cloth, and he (peace and blessings be upon him) put his saliva into your mouth, and he said words I do not know what they were. Sayyidah Fatimah (may Allah be pleased with her) had gone ahead of him (peace and blessings be upon him) in cutting the navel cord of Sayyiduna al-Hasan (may Allah be pleased with him), so he (peace and blessings be upon him) said: "Do not go ahead of me in this matter."
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 2754