Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) says: Seven things are Sunnah regarding a child on the seventh day: he is given a name, he is circumcised, the hair is removed from him, his ear is pierced, his aqiqah is performed, his head is shaved, he is smeared with the blood of the aqiqah (animal), and gold or silver equal to the weight of the hair of his head is given in charity.
Al-Tabarani recorded it in al-Awsat, and its narrators are thiqat (trustworthy).
Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) says: As for Hasan, Husayn and Muhsin, it was the Prophet (peace and blessings be upon him) who named them. He had their aqiqahs performed, had their heads shaved and gave in charity the equivalent of the weight of their (hair). The Prophet (peace and blessings be upon him) gave instructions concerning them, so their umbilical cords were cut and they were circumcised.
Al-Tabarani recorded it in al-Kabir; its chain contains Atiyyah al-Awfi, who is da'if (weak), though he has also been declared trustworthy.