I was just wondering if Arius and his followers used this verse as a proof text that, "there was a time in which He was not"?
Actually Athanasius employed Psalm 2:7 to demonstrate that Christ is worthy of worship...
Athanasius (297-373): But he is not in fact thus referred to; but the Father shews Him to be His own proper and only Son, saying, ‘Thou art My Son,’ and ‘This is My beloved Son, in whom I am well pleased.’ Accordingly the Angels ministered unto Him, as being one beyond themselves; and they worship Him, not as being greater in glory, but as being some one beyond all the creatures, and beyond themselves, and alone the Father’s proper Son according to essence.
NPNF2: Vol. VII,
Four Discourses Against the Arians, Oration II, §23.
Cyril of Jerusalem employed Psalm 2:7 to prove the eternal generation of the Son...
Cyril of Jerusalem (318-386): For the Son Himself says of the Father: “The Lord said to me, ‘You are my son; this day I have begotten you.’” Now “this day” is not recent, but eternal; “this day” is timeless, before all ages.
Fathers of the Church, Vol. 61, Catechesis XI.5 (Washington, D.C.: The Catholic University of America Press, Inc., 1969), p. 213.
However, Cyril is very apophatic as to
how the Son is begotten as seen in
Catechesis XI.11-12, at which point he urges caution when faced with Scripture's silence...
Cyril of Jerusalem (318-386): Why then do you busy yourself about things which even the Holy Spirit has not written of in the Scriptures? Though you understand not what is written, are you curious about what is not written? There are many questions in the Divine Scriptures; if we do not understand what is written, why weary ourselves about what is not written? It is enough to know that God begot One Only Son.
Fathers of the Church, Vol. 61, Catechesis XI.12 (Washington, D.C.: The Catholic University of America Press, Inc., 1969), p. 218.
Interestingly enough, the following Jesuit scholar states something about Cyril of Jerusalem that any Roman apologist would be loathe to admit...
Edward Yarnold, S.J.: Cyril subscribed to a form of
scriptura sola doctrine, stating categorically that every doctrinal statement must be based on the Scriptures: ‘let us not presume to speak of what is not in Scripture’ (
Cat. 16.24). Edward Yarnold, S.J.,
Cyril of Jerusalem, The Early Church Fathers (London: Routledge, 2000), p. 56.