All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger.
This meaning was authentically reported from the Prophet, sallallaahu ʻalayhi wa sallam, as we have underlined in the fatwa (243124) to which you were referred previously. As long as an authentic hadeeth was narrated in this regard, the statement of any other person is pointless. It does not matter if someone else makes a statement that conforms or clashes with the Prophet's statement. His statements are the acceptable, incontestable evidence, so what is the point of asking about the authenticity of someone else's statement when there is an authentic Marfoo’ hadeeth (directly attributed to the Prophet, sallallaahu ʻalayhi wa sallam) in this regard?
In any case, there is a report narrated on the authority of Ibn ʻAbbaas cited by Abu Nuʻaym Al-Asbahaani in his book Sifat Al-Jannah. It reads: Ibn ʻAbbaas said, “The people of Paradise shall be beardless, except for Moosa ibn ʻImraan (Moses), whose beard reaches down to his navel, and they will all bear their (worldly) names, except for Aadam, who shall be nicknamed Abu Muhammad.”
Allah knows best.