Bukhari

Hadith Commentary:
The indication of ninety is that the tip of the index finger (kalima finger) of the right hand is placed at its base, and the indication of one hundred is also very close to this.
By "evil" is meant fornication (zina) or the abundance of children born out of wedlock; other acts of immorality and wickedness are also intended.
If the barrier of Gog and Magog (Ya'juj wa Ma'juj) had opened up this much during the time of the Prophet sallallahu alayhi wa sallam, then now it is not known how much it has opened, and it is possible that it has become level or has hidden within the mountains, and the geographers have not come across it.
This is the opinion of Mawlana Waheed al-Zaman.
As for myself, wallahu a‘lam bis-sawab (Allah knows best what is correct), we have believed in what the Messenger of Allah sallallahu alayhi wa sallam has said.

Hadith Commentary:
➊
Among the Arabs, the number ninety is indicated in such a way that the tip of the index finger (the finger of testimony) is placed at the base of the thumb, then the thumb is joined with the finger in such a manner that a circular mark is formed inside.

➋
In the hadith, "filth" refers to the abundance of immorality and wickedness, and the prevalence of adultery and children born out of wedlock.
By Yajuj and Majuj (Gog and Magog) are meant those wild tribes from the far northeastern regions who used to attack the civilized nations of Europe and Asia through mountain passes.
Dhul-Qarnayn built a wall fifty miles long and one foot wide, blocking those passes, which could neither be scaled nor breached.
Near the Day of Judgment, this wall will be destroyed, and Yajuj and Majuj will surge forth in countless numbers like the waves of the sea, and will attack in the manner of a predatory animal that, freed from its cage, pounces upon its prey.
These two nations will unite and cause great turmoil, and this will occur near the Day of Judgment, as the Messenger of Allah (sallallahu alayhi wa sallam) has declared their attack to be a sign of the Hour.
(Sahih Muslim, Al-Fitan, Hadith 7285(2901))

➌
In the blessed era of the Messenger of Allah (sallallahu alayhi wa sallam), that wall had opened up a little, and this opening will continue to increase day by day until, near the Day of Judgment, it will be completely gone.
In the hadith, the Arabs are specifically mentioned because they were the first to accept Islam, and when tribulations begin, they will be the first to be afflicted by them.
(Fath al-Bari: 18/13)

Hadith Commentary:
1.
In the first hadith, "evil" refers to the tribulations (fitan) that appeared among the Arabs. Indeed, the tribulations that emerged after the martyrdom of Uthman (radi Allahu anhu) were extremely painful and distressing. Similarly, the Messenger of Allah (sallallahu alayhi wa sallam) saw that the wall of Gog and Magog (Ya’juj wa Ma’juj) had a hole the size of a ring made by two fingers. This hole is also a sign of the appearance of tribulations.

2.
In the hadith, "khubth" refers to immorality, wickedness, and sins. That is, when people begin to commit many sins, their destruction will certainly draw near, because when wickedness prevails, the good deeds of righteous people become overpowered and suppressed.

3.
You (sallallahu alayhi wa sallam) saw in a dream that after the treasures of Persia (Fars) and Rome (Rum) are obtained, an era of tribulations will ensue. This is because when conquests become numerous, the abundance of wealth and riches will give rise to envy, enmity, opposition, and hostility, which will serve as a prelude to bloodshed and widespread killing and plundering.

4.
Some commentators have interpreted this tribulation as referring to the Turks, who stirred up tribulations in Baghdad and other Islamic lands, which will continue until the emergence of the Dajjal. And Allah is the One whose help is sought.

Hadith Commentary:
In our time, many people are doubtful about this: when Gog and Magog (Ya’juj and Ma’juj) are such a large nation that not a single person among them dies until he has seen a thousand of his own descendants, then in which part of the world is this nation currently settled?
The geographers have surveyed the entire world; it is possible that a small island may have escaped their notice, but it is far-fetched to assume that such a vast land, inhabited by such a populous nation, would remain unseen.
Secondly, in this era, people climb very high mountains and even bore such tunnels through them that trains can pass through. So how could this wall possibly stop them? The hardest material in the world is steel, and even that can be easily pierced. No matter how high a wall is, people can climb it using tools.
With dynamite, it could be brought down in an instant.
The answer to these doubts is that we do not claim that the wall still exists and is holding back Gog and Magog.
However, until the time of the Prophet (sallallahu alayhi wa sallam), it certainly did exist, and at that time, industry and technology were not so widespread in the world, so it is not surprising that the wild tribes of Gog and Magog were held back by this wall.
As for the statement that no person among Gog and Magog dies until he has seen a thousand of his own descendants—
It is also possible that this refers to that era when human lifespans used to be a thousand or two thousand years, not to our time, when the average human lifespan has been reduced to a hundred or a hundred and twenty years.
After all, Gog and Magog are also human; just as our lifespans have decreased, so too would theirs. Now, as for the reports transmitted from the Companions (radi Allahu anhum) and the Followers (tabi‘in) regarding their stature and ears, their chains of transmission are not authentic or reliable. And among the nations that geographers have observed, two of the great nations are Gog and Magog.

(1)
Their lineage is from the descendants of Adam.
Other than Adam, they are not created from anyone else.

(2)
They are so numerous that the Muslim community will be only a thousandth part compared to these disbelievers.

(3)
Riot and corruption are inherent in their nature.
Dhul-Qarnayn sealed those mountain passes with iron to protect others from their attacks, through which they used to assault others.

(4)
In the blessed era of the Messenger of Allah (sallallahu alayhi wa sallam), a person saw this barrier of Dhul-Qarnayn, which was like an embroidered cloth.

(5)
During the time of the Messenger of Allah (sallallahu alayhi wa sallam), that wall had become somewhat weakened, so that a small hole had appeared in it.

(6)
Near the Day of Judgment, that wall will become level with the ground, and Yajuj and Majuj will surge forth like the waves of the sea.

(7)
The Messenger of Allah (sallallahu alayhi wa sallam) said:
The Hour will not be established
until the signs appear.
Among them is the attack of Yajuj and Majuj.
Soon after their onslaught, the Day of Judgment will be established.
The narrations transmitted regarding their stature do not meet the standards of authenticity set by the hadith scholars.

Hadith translation:
Yahya ibn Bukayr narrated to us, he said: Layth narrated to us, from ‘Uqayl, from Ibn Shihab, from ‘Urwah ibn Zubayr, from Zaynab bint Abi Salamah (radi Allahu anha), from Umm Habibah bint Abi Sufyan, from Zaynab bint Jahsh (radi Allahu anha) that the Prophet (sallallahu alayhi wa sallam) came to her in a state of anxiety.
Then he said that there is no deity except Allah, destruction will come upon the Arabs because of this evil which is drawing near; today Yajuj and Majuj have made such a hole in the wall, then the Prophet (sallallahu alayhi wa sallam) made a circle with his thumb and the finger next to it to show the size.
Umm al-Mu’minin Zaynab bint Jahsh (radi Allahu anha) narrated that I asked: O Messenger of Allah! Will we be destroyed even though there are righteous people among us? He replied: When immorality and wickedness increase,
(then surely there will be destruction).

Hadith Commentary:

Hadith Commentary: Benefits and Issues: The Prophet specified the Arabs because, at that time, they were the majority and dominant among the Muslims, and they alone held authority and power. This hadith also proves that, "Along with the flour, the bran is also ground," meaning that in the majority of the wicked, the minority of the righteous cannot be saved from destruction, because they do not even attempt to put up a barrier against the majority, or their efforts go in vain.