Eternal Generation

Quando Pater coaeternum sibi Verbum genuit, tunc dixit, Filius meus es tu. In verbo dixit, et Filius meus es tu, genuit. Quia vero generatio transitora non est, dicitur hodie; et quia perfecta, genui. Ideo enim per praeteritum dicitur, ne putetur imperfecta; et ideo per hodie quod est praesens, ne transacta. Hugo De Sancte Victore, Miscellanea, Liber I, Tit CLIX, De Filii Dei generatione aeterna Source: Migne PL 177.558a

When the Father begot the coeternal Word from Himself, then 'He said, You are my son.' 1 With speech, 'He said', and with 'you are my son,' He begot. But because this is not a transitory generation, he then says 'today,' and because it is completed, 'I have begot.' Therefore it is spoken in the past tense, lest it might be thought to be incomplete, and as 'today' because it is enduring, not transitory. Hugh Of Saint Victor, Miscellanea, Book 1, Chapter 159, On The Eternal Generation of the Son of God 1 Ps 2.7