The End Times Revelation of the Ark of the Covenant
Then God's temple in heaven was opened, and the ark of his covenant was seen within his temple. (Rev 11:19)
The above passage of the Apocalypse is the last mention of the Ark of the Covenant in the Bible, and is closely associated with the Woman Adorned with the Sun in the following chapter. Catholics and Orthodox alike traditionally hold that the Ark of the Covenant prefigures the Blessed Virgin Mary as the Theotokos (which means "God-bearer" in Greek); and similarly accept that the purpose of the juxtaposition between the vision of the Ark at the end of Rev 11 with the appearance of the Woman Adorned with the Sun at the start of Rev 12 is to intentionally draw a comparison between these archetypes. The Ark of the Covenant, which housed the presence of God in the form of the Divine Shekhinah Glory, directly prefigures the Woman who would bear the Eternal Logos within her own body. Indeed the Virgin Mary has been equated with the Ark of the New Covenant since the earliest days of Christianity. Writing in the third century, for example, St. Gregory Thaumaturgus (c.213-c.270), makes this analogy fully explicit: “The ark is verily the holy Virgin, gilded within and without, who received the treasure of universal sanctification. Arise, O Lord, from the Father’s bosom, to raise up again the ruined race of our first parent” St. Gregory Thaumaturgus (Orat. in Deip. Annunciat. Int. Opp. S. Greg. Thaumaturg) The fact that the exposition of the Ark of the Covenant at the end of the cycle concerning the Two Witnesses is immediately followed by the "Great Sign" seen in heaven at the opening of Rev 12 - a vision of the Theotokos, suggests that these two elements are inextricably linked. At the same time, the vision of the Ark of the Covenant in the Apocalypse also appears to be closely related to the widespread belief in ancient Judaism that the Ark would be discovered towards the end of the world, before the final coming of the Messiah. We can find an example of this expectation in the recently discovered Hebrew pseudepigraphical text Treatise of the Vessels (the dating of which is uncertain, see here for more info), which claims that a portion of the treasures of King Solomon's Temple, including the Ark of the Covenant, were hidden by a number of Levites and prophets before the sack of the Temple by the Babylonian forces of King Nebuchadnezzar. The Treatise of the Vessels states that the Ark was hidden away in an unspecified location, and would "not be revealed until the day of the coming of the Messiah son of David" (See Davila, J. Old Testament Pseudepigrapha: More Noncanonical Scriptures Vol 1, Eerdmans, 2013).
Most importantly for Catholics however, is the fact that the rediscovery of the Lost Ark towards the end time is prophesied in the deuterocanonical Second Book of Maccabees - which was infallibly defined by the Catholic Church as a divinely inspired work during the Council of Trent in the 16th century, and is thus considered to be part of Divine Revelation:
These same records also tell us that Jeremiah, acting under divine guidance, commanded the Tent of the Lord's Presence and the Covenant Box to follow him to the mountain where Moses had looked down on the land which God had promised our people.When Jeremiah got to the mountain, he found a huge cave and there he hid the Tent of the Lord's Presence, the Covenant Box, and the altar of incense. Then he sealed up the entrance.
Some of Jeremiah's friends tried to follow him and mark the way, but they could not find the cave.When Jeremiah learned what they had done, he reprimanded them, saying:
No one must know about this place until God gathers his people together again and shows them mercy.At that time he will reveal where these things are hidden, and the dazzling light of his presence will be seen in the cloud, as it was in the time of Moses and on the occasion when Solomon prayed that the Temple might be dedicated in holy splendor.
We are also told how the wise King Solomon offered a sacrifice of dedication at the completion of the Temple,and that when he prayed, fire came down from heaven and consumed the sacrifices, just as it had done earlier when Moses prayed. (2Macc 2:4-12) We should take note here that the Catholic Encyclopedia asserts that since the above text from 2 Maccabees is quoting from a source outside of the Bible, it cannot be regarded to have Divine inspiration: According to many commentators, the letter from which the above-cited lines are supposed to have been copied cannot be regarded as possessing Divine authority; for, as a rule, a citation remains in the Bible what it was outside of the inspired writing... (Souvay, C.(1907).Ark of the Covenant. In The Catholic Encyclopedia.New York: Robert Appleton Company. See here for the original article).
However this is one of the few instances in which the material contained in an article in the Catholic Encyclopedia is simply outdated and mistaken (having been composed in the early 20th century), as this is quite clearly at odds with subsequent papal teachings on the extent of Divine inspiration in the content of Public Revelation. As Pope Pius XII states in his 1950 papal encyclical Humani Generis: "If, however, the ancient sacred writers have taken anything from popular narrations (and this may be conceded), it must never be forgotten that they did so with the help of divine inspiration, through which they were rendered immune from any error in selecting and evaluating those documents." Pius XII Humani Generis38)
As Pope Leo XIII further confirms in his 1893 papal encyclical Providentissimus Deus: "But it is absolutely wrong and forbidden, either to narrow inspiration to certain parts only of Holy Scripture, or to admit that the sacred writer has erred... For all the books which the Church receives as sacred and canonical, are written wholly and entirely, with all their parts, at the dictation of the Holy Ghost; and so far is it from being possible that any error can co-exist with inspiration, that inspiration not only is essentially incompatible with error, but excludes and rejects it as absolutely and necessarily as it is impossible that God Himself, the supreme Truth, can utter that which is not true. This is the ancient and unchanging faith of the Church, solemnly defined in the Councils of Florence and of Trent, and finally confirmed and more expressly formulated by the Council of the Vatican... It follows that those who maintain that an error is possible in any genuine passage of the sacred writings, either pervert the Catholic notion of inspiration, or make God the author of such error." (Pope Leo XIII Providentissimus Deus, 20-21)
In citing the above material concerning the whereabouts of the Ark of the Covenant, the author of 2 Maccabees clearly intended that his audience should accept this account as genuine, and was working under Divine inspiration in doing so. So according to Church teaching, Catholics are therefore compelled to accept not only that the Ark of the Covenant was hidden by the Prophet Jeremiah on the mountain where Moses saw the Promised Land, but also that it will one day be miraculously revealed towards the end of time by the descent of the Divine Presence in dazzling light, like the theophany at Sinai, after the eschatological ingathering of the Jews to the land of Israel. All other options, such as that the Ark was hidden beneath the Temple Mount, carried off to Axum in Ethiopia, was captured by the Babylonians, or destroyed, should therefore be discounted, since Scripture itself tells us its exact location. According to Deut 34 the mountain from where Moses looked down to see the Promised Land is Mount Nebo, located in modern day Jordan:
Then Moses went up from the plains of Moab to Mount Nebo, to the top of Pisgah, which is opposite Jericho. And the LORD showed him all the land, Gilead as far as Dan, all Naphtali, the land of Ephraim and Manasseh, all the land of Judah as far as the western sea, the Negeb, and the Plain, that is, the Valley of Jericho the city of palm trees, as far as Zoar. And the LORD said to him, “This is the land of which I swore to Abraham, to Isaac, and to Jacob, ‘I will give it to your offspring.’ I have let you see it with your eyes, but you shall not go over there.” So Moses the servant of the LORD died there in the land of Moab, according to the word of the LORD, and he buried him in the valley in the land of Moab opposite Beth-peor; but no one knows the place of his burial to this day.
Mount Nebo in Jordan, which 2Macc tells us is the final resting place of the Ark of the Covenant
The prophecy that God's chosen people would be granted mercy at the time of the revelation of the Lost Ark, after the eschatological ingathering mentioned in 2Macc 2:4-12, can only be equated with the end time conversion of the Jews - which the Catechism states must take place before the Second Coming of Christ: The glorious Messiah's coming is suspended at every moment of history until his recognition by "all Israel", for "a hardening has come upon part of Israel" in their "unbelief" toward Jesus. St. Peter says to the Jews of Jerusalem after Pentecost: "Repent therefore, and turn again, that your sins may be blotted out, that times of refreshing may come from the presence of the Lord, and that he may send the Christ appointed for you, Jesus, whom heaven must receive until the time for establishing all that God spoke by the mouth of his holy prophets from of old." St. Paul echoes him: "For if their rejection means the reconciliation of the world, what will their acceptance mean but life from the dead?" The "full inclusion" of the Jews in the Messiah's salvation, in the wake of "the full number of the Gentiles", will enable the People of God to achieve "the measure of the stature of the fullness of Christ", in which "God may be all in all". (CCC 674) It would thus appear that the eschatological discovery of the Ark of the Covenant prophesied in 2Macc 2:4-12 is the primary catalyst for the future conversion of the Jews - an event which the Apocalypse links to the appearance of the Great Sign seen in Heaven during the birth pangs of the coming of the Messiah: Then God's temple in heaven was opened, and the ark of his covenant was seen within his temple. There were flashes of lightning, rumblings, peals of thunder, an earthquake, and heavy hail. And a great sign appeared in heaven: a woman clothed with the sun, with the moon under her feet, and on her head a crown of twelve stars. She was pregnant and was crying out in birth pains and the agony of giving birth. (Rev 11:19, 12:1-2) Could the appearance of the Great Sign in Heaven be one and the same as 2 Maccabees' prophecy of God's presence descending upon Mount Nebo in dazzling light, at a time when great mercy would be shown to the Jews? It seems quite plausible that it would require an event on the magnitude of the discovery of the most revered religious object in Judaism to effect a mass Jewish conversion to the Catholic Church. But the revelation of the Ark would only truly be able to win Jewish converts if its discovery was specifically related to Catholicism itself, such as being involved with a major Marian apparition, the fulfillment of a Catholic prophecy, or that it led to some radical new understanding of Scripture proving the truth of the Catholic faith. Reading 2Macc 2:4-12 side-by-side as a theological diptych with the above section of the Apocalypse, we are certainly left with the distinct impression that the rediscovery of the Ark of the Covenant brought about by the appearance of the Divine presence in the Shekhinah Glory would be accompanied by the Great Sign in Heaven - which is described in the Apocalypse as a vision of the Woman Adorned with the Sun. By combining both texts, we appear to have a prophecy of a future Marian apparition in the vicinity of Mount Nebo that leads to the discovery of the Ark of the Covenant, which has been lost to history for the past 2,600 years. And it would also seem that this Marian apparition coincides with the appearance of the Divine Shekhinah Glory to reveal the Ark of the Covenant. Could it be that the Theotokos herself will appear with the manifestation of her Spouse the Holy Spirit in the Shekhinah Glory, and reveal not only the location of the Ark of the Covenant, but also leading to the the understanding that the Blessed Virgin is in fact its physical embodiment - thus securing the future conversion of the Jews promised in the writings of the New Testament? A detailed discussion of the role of the Ark of the Covenant in prophetic events can be found in chapter 10 of Desmond Birch's excellent work Trial, Tribulation & Triumph, which is widely considered to be the best book dealing with the subject of Catholic prophecy.