Mary is the Mountain of Zion

The mountain of Ephraim can designate the all-blessed Mary, always Virgin, Mother of God. For she was a mountain, she who, by the dignity of her election, surpasses every elected creature, however great. Was not Mary a very high mountain, she who accumulated a peak of merit, above all the choirs of the Angels, up to the throne of the divinity, and thus was able to conceive the eternal Word?

Isaiah, prophesying about her exalted dignity, says: "It shall come to pass in the future, that the mountain which bears the house of the Lord shall be set on the top of the mountains." Indeed, she was a mountain, set over all mountains, for Mary's greatness shines above all the saints.

Pope Saint Gregory the Great