here again, like on the other thread on the Greek, you seem to think that what others post is wrong, and you are always right!
Yet again you are WRONG! Both Tertullian and Cyprian wrote in the Old Latin from, which Jerome revised for his Vulgate, or common language version, which indeed is different. This means, that both Tertullian and Cyprian, who read and wrote Greek, had this verse in their Greek and Latin First Epistle of John, over ONE HUNDERED YEARS EARLIER!
Tertullian
"Ita connexus Patris in Filio et Filii in Paracleto, tres efficit coharentes, alterum ex altere, qui tres unum sunt, non unus, quomodo dictum est, Ego et Pater unum sumus." (Against Praxeas XXV)
Tertullian uses John 10:30 with 1 John 5:7, which are on the essential unity of the Persons in the Godhead. Secondly, where, if not from 1 John 5:7, does Tertullian get the phrase, “qui tres unum sunt”? Thirdly, what does Tertullian mean with the phrase, “quomodo dictum est” (in the same manner which it was said)? And then quote from John 10:30? Fourthly, though, like Cyprian, Tertullian was of the Latin Church, yet we know that he “wrote particularly in Latin, but also in Greek. He also sometimes used a Latin Bible, sometimes a Greek, probably oftener the former than the latter. It is improbable that his Greek Bible was very different in text from the Greek text underlying his Latin Bible” (A Souter; The Text and canon of the New Testament, p.79). Frederic Kenyon adds, that Tertullian “seems often to have made his own translations from the Greek” (The Text of the Greek Bible, p.136)
Cyprian
“Dicit Dominus, ego et Pater unum sumus, et iterum de Patre, et Filio et Spiritu Sancto, scriptum est, et tres unum sunt” (De Unitate Ecclesiae, Op.p.109)
“The Lord said, I and the Father are one, and again of the Father, and of the Son, and of the Holy Spirit, it is written: and these three are one”
The first quotation is from John 10:30, where our Lord is speaking of the essential unity of Himself and the Father. “I and the Father”, two Persons, which is further shown by the use of the masculine, plural “sumus” (lit. “We are”. It is then followed by the neuter “hen” (lit “one thing”; not the masculine “heis “ ”one person”).
Cyprian then goes on to say, “et iterum...scriptum est”, that is, “and again...it is written”. It must be mentioned here, that whenever Cyprian was referring to, or quoting from a Scripture passage. Where else, besides 1 John 5:7 in the entire Bible do words even similar to these appear?
Now tell me that they are not quoting from 1 John 5:7, in the THIRD century?