The Shadowing Of Mary

Et respondens angelus, dixit ei: Spiritus sanctus superveniet in te, et virtus Altissimi obumbrabit tibi. Non virili, inquit, quod non cognoscis, semine, sed Spiritus sancti quo impleris, opere concipies, Erit in te conceptio, libido non erit. Concupiscentiae non erit aestus, ubi umbram faciet Spiritus sanctus. Verum in eo quod ait, Et virtus Altissimi obumbravit tibi, potest etiam incarnati Salvatoris utraque natura designari. Umbra quippe a lumine solet et corpore formari. Et cui obumbratur, lumine quidem vel calore solis quantum sufficit reficitur, sed ipse solis ardor, ne ferri nequeat, interposita vel nubecula levi, vel quolibet alio corpore temperatur. Beatae itaque Virgini, quia quasi pura homo omnem plenitudinem divinitatis corporaliter capere nequibat, virtus Altissimi obumbravit, id est, incorporea lux divinitatis corpus in ea susceptit humanitatis. Sanctus Beda,In Lucae Evangelium Expositio, Liber Primus Source: Migne PL 92.318d-319a

And the angel answered her, saying, 'The Holy Spirit shall come upon you, and the power of the Most High will cover you.' 1 You shall not conceive by man's seed, which you do not know, but by the Holy Spirit, by whom you shall be filled. There shall be in you a conception without lust. When the Holy Spirit brings shade there shall be no heat of concupiscence. Truly in this which is said, 'And the power of the Most High will cover you,' it is indeed possible to distinguish the incarnation of the Saviour in both natures. Certainly a shadow is accustomed to be formed by the sun and a body. And the one who is shadowed from the light or the heat of the sun is refreshed in as much as shade is provided, and so against that blaze of the sun, lest it not be able to be borne, there is interposed a light cloud, or some other body, which tempers it. Therefore the power of the Most High shadowed the blessed Virgin, because even a pure human cannot corporeally contain the whole plenitude of Divinity, that is, the incorporeal light of Divinity that was taking up a human body in her. Saint Bede, Commentary On The Gospel of Saint Luke, Book 1 1 Lk 1.35