This is the front center portion of an Osiris figure wearing Heb Sed Cloak with double, incised line on edges of cloak. The right arm is emerging from the cloak. It is highly polished and of fine quality. See documentation for related objects.
From Nubia (Sudan) Gebel Barkal, 905. 1916: excavated by the Harvard University-Museum of Fine Arts Expedition; assigned to the MFA by the government of Sudan.
Harvard University—Boston Museum of Fine Arts Expedition