I’m only human; members of my family. The pairing of flesh and blood dates back very far. In English it appears in the Bible (Matthew 16:17; Ephesians 6:12), Shakespeare’s Julius Caesar (3.1: “and men are flesh and blood, and apprehensive”), and numerous other writings, mostly in the meaning of being only human (Thomas Hood, “The Song of the Shirt”: “Oh God! that bread should be so dear and flesh and blood so cheap!”). The other sense, of blood relations, appeared in a 1300 manuscript (“He . . . es your aun fless and blod”), and numerous other early sources, as well as in Shakespeare’s The Merchant of Venice (where Gobbo says to his son, “If thou be Launcelot, thou art mine own flesh and blood,” 2.2).