So Cyril
speaks frequently of the Holy Spirit as proceeding from the
Father and being (ειναι) and abiding
(μένειν) in the
Son; as also of the Spirit as being of the Son and having His
nature in Him (ἐξ
αὐτοῦ καὶ
ἐμπεφυκὼς
αὐτῷ). The idea seems to have
been that as the Son is in the bosom of the Father so the Spirit is in
the bosom of the Son. The Spirit was compared again to the
energy, the natural, living energy, of the Son
(ἐνέργεια
φυσικὴ καὶ
ζωσα, τὸ
ἐνεργὲς τοῦ
υἱοῦ), Cyril, Dial 7 ad
Hermiam. Such terms as προβολεὺς
ἐκφαντορικοῦ
πνεύματος,
the Producer, or, Emitter of the revealing Spirit, and
the ἔκφανσις or
ἔλλαμψις, the
revealing, the forth-shewing, were also used to express
the procession of the one eternal Person from the Other as like the
emission or forth-shewing of light from light.