Jeremiah 30:7 Alas! for that day is great, so that none is like it: it is even the time of Jacob’s trouble; but he shall be saved out of it.
In context it can be seen as a prophecy of Israel’s time of trouble just prior to their final deliverance.
Jeremiah 30:1 The word that came to Jeremiah from the LORD, saying, 2 Thus speaketh the LORD God of Israel, saying, Write thee all the words that I have spoken unto thee in a book. 3 For, lo, the days come, saith the LORD, that I will bring again the captivity of my people Israel and Judah, saith the LORD: and I will cause them to return to the land that I gave to their fathers, and they shall possess it. 4 And these are the words that the LORD spake concerning Israel and concerning Judah. 5 For thus saith the LORD; We have heard a voice of trembling, of fear, and not of peace. 6 Ask ye now, and see whether a man doth travail with child? wherefore do I see every man with his hands on his loins, as a woman in travail, and all faces are turned into paleness? 7 Alas! for that day is great, so that none is like it: it is even the time of Jacob’s trouble; but he shall be saved out of it. 8 For it shall come to pass in that day, saith the LORD of hosts, that I will break his yoke from off thy neck, and will burst thy bonds, and strangers shall no more serve themselves of him: 9 But they shall serve the LORD their God, and David their king, whom I will raise up unto them.
‘bring again the captivity of my people Israel and Judah’ means to bring back the whole of the twelve tribes from dispersion among the nations. It is not the return from Babylon being spoken of because the monarchy of the house of David was not restored. When Zedekiah (the last king) was taken captive the crown was not to be restored until the one came whose right it is to sit upon the throne of David.
Ezekiel 21:25 And thou, profane wicked prince of Israel, whose day is come, when iniquity shall have an end, 26 Thus saith the Lord GOD; Remove the diadem, and take off the crown: this shall not be the same: exalt him that is low, and abase him that is high. 27 I will overturn, overturn, overturn, it: and it shall be no more, until he come whose right it is; and I will give it him.
Jesus is the one whose right it is to be king over the house of Jacob (Israel).
Luke 1:31 And, behold, thou shalt conceive in thy womb, and bring forth a son, and shalt call his name JESUS. 32 He shall be great, and shall be called the Son of the Highest: and the Lord God shall give unto him the throne of his father David: 33 And he shall reign over the house of Jacob for ever; and of his kingdom there shall be no end.
After the Jews rejected their rightful king they were to be made desolate. From AD70 Jerusalem was to be trodden down of the gentiles (non Jews) until the times of the gentiles be fulfilled.
Luke 21:24 And they shall fall by the edge of the sword, and shall be led away captive into all nations: and Jerusalem shall be trodden down of the Gentiles, until the times of the Gentiles be fulfilled.
In 1948 Israel became a Nation State and in 1967 Jerusalem was taken back into Jewish hands. The scene is now almost set for the final phase of the time of Jacob’s trouble.
Jerusalem is (as we already see) to become a burdensome stone for all people. The conflict will end in a final siege of Jerusalem and overthrow of the Jews.
Zechariah 12:2 Behold, I will make Jerusalem a cup of trembling unto all the people round about, when they shall be in the siege both against Judah and against Jerusalem. 3 And in that day will I make Jerusalem a burdensome stone for all people: all that burden themselves with it shall be cut in pieces, though all the people of the earth be gathered together against it.
Zechariah 14:2 For I will gather all nations against Jerusalem to battle; and the city shall be taken, and the houses rifled, and the women ravished; and half of the city shall go forth into captivity, and the residue of the people shall not be cut off from the city.
This is the day of Jacob’s trouble that Jeremiah is speaking of. The way the house of Jacob will be saved is by the return of Christ with his saints described as the Lord going forth.
Zechariah 14:3 Then shall the LORD go forth, and fight against those nations, as when he fought in the day of battle. 4 And his feet shall stand in that day upon the mount of Olives, which is before Jerusalem on the east, and the mount of Olives shall cleave in the midst thereof toward the east and toward the west, and there shall be a very great valley; and half of the mountain shall remove toward the north, and half of it toward the south. 5 And ye shall flee to the valley of the mountains; for the valley of the mountains shall reach unto Azal: yea, ye shall flee, like as ye fled from before the earthquake in the days of Uzziah king of Judah: and the LORD my God shall come, and all the saints with thee.
The rejoining of the two tribes with the ten is prophesied in Ezekiel as follows:
Ezekiel 37:16 Moreover, thou son of man, take thee one stick, and write upon it, For Judah, and for the children of Israel his companions: then take another stick, and write upon it, For Joseph, the stick of Ephraim, and for all the house of Israel his companions: 17 And join them one to another into one stick; and they shall become one in thine hand...19 Say unto them, Thus saith the Lord GOD; Behold, I will take the stick of Joseph, which is in the hand of Ephraim, and the tribes of Israel his fellows, and will put them with him, even with the stick of Judah, and make them one stick, and they shall be one in mine hand... 21 And say unto them, Thus saith the Lord GOD; Behold, I will take the children of Israel from among the heathen, whither they be gone, and will gather them on every side, and bring them into their own land: 22 And I will make them one nation in the land upon the mountains of Israel; and one king shall be king to them all: and they shall be no more two nations, neither shall they be divided into two kingdoms any more at all: 23...I will save them out of all their dwellingplaces, wherein they have sinned, and will cleanse them: so shall they be my people, and I will be their God. 24 And David my servant shall be king over them; and they all shall have one shepherd: they shall also walk in my judgments, and observe my statutes, and do them. 25 And they shall dwell in the land that I have given unto Jacob my servant, wherein your fathers have dwelt; and they shall dwell therein, even they, and their children, and their children’s children for ever: and my servant David shall be their prince for ever.
More details of the time of Jacob’s trouble are given in Ezekiel 38 and 39. Gog of the land of Magog is the leader of the invasion and the nations involved are denoted by the names of the progeny of Noah (Genesis 10) who settled in the lands after the confusion of languages at Babel. Some of the names - Persia, Ethiopia and Libya are still recognisable today.
There are of course many more prophecies which refer to the same event but I think there is sufficient here to answer your question.
I hope you have found this helpful.
May God bless you,