While Howard supposed that the New Testament writers took their Old Testament quotations directly from Septuagint manuscripts (which he also supposed contained the Tetragrammaton), Philip Wesley Comfort believes they took them from "Testimonia" (excerpts from the Old Testament that Christians compiled as proof texts for their claims). He recognizes that the earliest extant evidence of the use of nomina sacra is found in second-century manuscripts of the Septuagint rather than of such "Testimonia" or of the New Testament, and comments: "Regardless of whether the nomina sacra were invented in the testimonia stage or in early Christian Greek Old Testament manuscripts (i.e., first century), the significance is that they may have existed in written form before the Gospels and Epistles were written. As such, some of the New Testament writers themselves could have adopted these forms when they wrote their books. The presence of the nomina sacra in all the earliest Christian manuscripts dating from the early second century necessitates that it was a widespread practice established much earlier. If we place the origin of that practice to the autographs and/or early publications of the New Testament writings, it explains the universal proliferation thereafter." He pictures the "nomina sacra" entering Christian copies of the Septuagint in the same way as in Papyrus Oxyrhynchus 656 the original scribe left gaps for someone capable of writing Hebrew or Palaeo-Hebrew to fill in with the Tetragrammaton, but that were in fact filled with the word κύριος.