Possibly leg fragment from sphinx. Two sculpted surfaces one of which has a double incised curvy line.
From Nubia (Sudan) Gebel Barkal, between 520 and circular well B-1000. 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
Egyptian, New Kingdom, Dynasty 18, reign of Amenhotep II, 1427–1400 B.C.