Niketas David Paphlagon (Greek: Νικήτας Δαβὶδ Παφλαγών), also known as Nicetas the Paphlagonian or Nicetas of Paphlagonia, was a prolific Byzantine Greek writer of the late 9th and early 10th century.[1]
Also, Didymus Alexandririus, in his commentary on the same passage, reads, “the Spirit, Water, and Blood,” without mentioning “ the Three in Heaven and so he doth in his book of the Holy Ghost, where lie seems to omit nothing that he could find for his purpose : and so doth Gregory Nazianzen in his xxxviith oration concerning the Holy Ghost; and also Nicetas in his commentary on Gregory Nazianzen’s xlivth oration : And here it is further observable, that, as the Eusebians bad contended, that “ the Father, Son, and Holy Ghost” were not to be connumerated, because they were things of a different kind ; Nazianzen and Nicetas answer, that they might be connumerated, because St. John connumerates three things not substantial, namely, “the Spirit, the Water, and the Blood.”
A Course of Critical Lectures: Or, Systematical Theology, in Four Parts, Viz : Theology, Demonology, Christology, and Anthropology (1825) http://books.google.com/books?id=BiY_AAAAYAAJ&pg=PA52
John Samuel Thompson
It is here worthy of remark, that when the Eusebians urged that the Father, Son, and Spirit, should not be considered as one, but different things ; Gregory Nazianzen, and Nicetas, answer that they might be considered as one, because John calls the Spirit, water, and blood one.
With this explanation the passage from Gregory will be intelligible: ... It may here be urged, that Gregory omitted the clause purposely, as not contributing to strengthen his argument. The same may be alleged of a similar passage in Nicetas, the Commentator on Gregory, as adduced by Matthaei: Nicetas is there illustrating a different part of his author; but has evidently borrowed his reasoning, and almost his words, from that which I have translated. He too omits the final clause.—At any rate it is remarkable, that the clause in question appears so seldom in the writings of the Fathers: connected with the sentence preceding, it was capable of being converted to some use by persons, who knew the mystical interpretation of Spirit, Blood, and Water, and who for the most part were not averse from that kind of exposition.