The Gate of Mary

Et infra dicit prophet vidisse se in monte alto nimis aedificationem civitatis, cujus portae plurimae significatur; una tamen clausa describitur, de qua sic ait: Et converti me secundum viam portae sanctorum exterioris , quae respicit ad Orientem, et haec erat clausa. Et ait ad me Dominus: Porta haec claus erit, et non aperietur, et nemo transibit per eam; quoniam Dominus Deus Israel transibit eam. Eritque clausa, quoniam dux hic sedebit in ea, ut manducet panem in conspectu Domini. Secundum viam Aetam portae intrabit, et secundum viam ejus exibit. Quae est haec porta, nisi Maria; ideo clausa, quia virgo? Porta igitur Maria, per quam Christus intravit in hunc mundum, quando virginali fusus est partu, et genitalia virginitatis claustra non solvit. Mansit intemertatum septum pudoris, et inviolata integritatis duravere signacula; cum exiret ex virgine, cujus altitudinem mundus sustinere non posset. Haec, inquit, porta clausa erit, et non aperietur. Bona porta  Maria, quae clausa erat, et non aperiebatur. Transivit per eam Christus, sed non aperuit. Et ut doceamus quia portam habet omnis homo, per quam Christus ingreditur: Tollite, inquit, portas, principes, vestras, et elevamini portae aeternales, et introibit Rex gloriae. Quanto magis ergo porta erat in Maria, in qua sedit Christus, et exivit? Est ergo et porta ventris, sed non clausa semper: verum una sola potuit manere clausa, per quam sine dispendio claustrorum genitalium virginis partus exivit. Ideo ait propheta  Porta haec clausa erit: non aperietur, et nemo transibit per eam, hoc est, nemo hominem; quoniam Dominus, inuqit, Deus Israel transibit per eam. Eritque clausa, id est, ante et post transitum Domini erit clausa: et non aperietur a quoquam, nec aperta est; quoniam habuit semper januam suam Christum, qui dixit: Ego sum janua , quam nemo ab ea potuit avellere. Sanctus Ambrosius Mediolanensis, De Institutione Virginis, Caput VIII

And the Prophet himself saw on a very high mountain a city built, 1 of which many gates were pointed out, and one was described as closed, concerning which it was said, 'And He turned me to the way of the gate of the outer holy places, which looked to the east, and it was closed. And the Lord said to me: This gate shall be closed and it shall not be opened, and no one shall pass through it, because the Lord God of Israel shall pass through it. And it shall be closed because the prince shall sit there, that he eat his bread in the sight of the Lord. According to the way of the gate He shall enter the age and by this way he shall come forth 2 And what is this gate but Mary, and why is it closed, but that she is a virgin? Thus the gate of Mary, through which Christ entered into this world, when he was born of a virgin, and the closed parts of virginity were not opened. The barrier of modesty remained undefiled and inviolate the integrity of the enduring seal; when he came out from the virgin, his greatness the world was not able to endure. This gate shall be closed, it was said,and it shall not be opened. Mary is the good gate, which was closed and was not opened. Christ passed through her and it was not opened. And we teach that every man has a gate, through which Christ enters. 'Take up your gates, princes, and lift the eternal portals, and the king of glory will enter.'3 How much more was Mary a gate in which Christ sat and He came out? It is, therefore, the gate of the womb, but it is not always closed; truly one alone was able to remain closed, through which came, without loss of the sealed parts of virginity, birth. Therefore the Prophet says, 'This gate shall be closed, and it shall not open, and no one shall pass through it,'  that is, no man; because the Lord says the God of Israel shall pass through it. And it shall be closed, that is, before and after the Lord passes through, and it shall not open for anyone, nor was it open; because He has always his own gate, Christ, who said: 'I am the gate' 4 which no one is able to remove. Saint Ambrose, On The Birth of the Virgin, Chap 8 1 Ez 40.2 2 Ez 44.1 - 3 Ps 23.7 4 Jn 10.7