Several early sources which one might expect to include the Comma Johanneum in fact omit it. For example, although Clement of Alexandria () places a strong emphasis on the Trinity, his quotation of 1 John 5:8 does not include the Comma. Tertullian, in his "Against Praxeas" (), supports a Trinitarian view by quoting John 10:30. Jerome's writings of the fourth century give no evidence that he was aware of the Comma's existence. (The Codex Fuldensis, of 546, contains a copy of Jerome's "Prologue to the Canonical Gospels" which seems to reference the Comma, but the Codex's version of 1 John omits it, which has led many to believe that the "Prologue"'s reference is spurious.)