How authentic is the Hadith: "Adam exited Paradise, and his language was Syriac, and he will not return to it"? And does it take the ruling of Marfu' (attributable to the Prophet) if it is authentically disconnected (Maqtu')?

This Hadith was narrated by Al-Hasan Al-Basri, who was a Tabi'i (successor to the companions), and a Tabi'i's mawquf (statement attributed to a companion) is called maqtu' (disconnected), and it does not have the ruling of a marfu' (statement attributed to the Prophet). A marfu' is what was the saying of a Companion in which there was no room for personal opinion and who was not known for taking from the People of the Book.