Here are the most important and authentic (ṣaḥīḥ or ḥasan) hadiths about Yajuj and Majuj (Gog and Magog) in Sunni Islam, grouped by topic. All references are from the Six Books or other widely accepted collections.

1. Their physical description and imprisonment behind the barrier

• The Prophet ﷺ said:
  “Today the gate of Yajuj and Majuj has been opened this much,” and he made a circle with his thumb and index finger.
  (Bukhari 3346, Muslim 2880)
• Zaynab bint Jahsh (ra) said: The Prophet ﷺ woke up red-faced and said:
  “Woe to the Arabs from an evil that has drawn near! Today a hole has been made in the barrier of Yajuj and Majuj like this,” and he made a circle of 90 or 100 with his fingers.
  (Bukhari 3346, Muslim 2880)
• They try every day to break through the wall, say “In sha Allah” (they forget it), and it closes again until the day Allah wills their release.
  (Muslim 2880 – long hadith of Zaynab)

2. They will be the overwhelming majority of the people on earth when released

• The Prophet ﷺ said:
  “Allah will say on the Day of Resurrection: ‘O Adam!’ … Then Allah will say: ‘Send forth those who are destined for Hell.’ He will ask: ‘How many?’ Allah will say: ‘From every thousand, take out nine hundred and ninety-nine.’ … That is when the child’s hair turns grey … That is the day when the shin will be laid bare.”
  → The Prophet then explained that the 999 are from Yajuj and Majuj, and only 1 out of 1,000 humans is saved.
  (Bukhari 3348, 4741, 6530, 7483; Muslim 222 – slightly different wordings)

This is the most commonly cited hadith for the claim that Yajuj and Majuj will be the vast majority of the people of Hell.3. How they are finally killedThere are two authentic versions:A. Killed by a natural plague / worm in their necks (most common authentic narration)

• The Prophet ﷺ said:
  “Jesus son of Mary will descend … then Allah will send against Yajuj and Majuj a disease (or worms) in their necks, and they will all die in a single morning like the death of a single soul.”
  (Muslim 2897 – from al-Nawwas ibn Sam‘an, very long hadith about the Dajjal and Jesus)

B. Killed by a single night’s plague sent by Allah (variant wording)

• “Allah will send a plague upon them and they will all perish as one soul perishes.”
  (Ahmad 22818, graded ṣaḥīḥ by al-Albani)

4. Other authentic details

• They will drink up Lake Tiberias (Sea of Galilee) completely. The last of them will pass by and say, “There was once water here.” (Muslim 2897)
• They will shoot their arrows into the sky, and they will come back stained with blood (as a trial for people). (Muslim 2897)
• No country will escape their rampage except Mecca and Medina (protected by angels). (Bukhari 7135)

5. Weak or fabricated hadiths (commonly circulated but not authentic)

• “Yajuj and Majuj are from the children of Adam and are 1/10 of mankind” → fabricated.
• “They are 999 to every 1 human” (exact ratio reversed) → no authentic source.
• “They have flat faces, small eyes, and are Turks/Mongols/Chinese” → most of these ethnic identifications are weak or forged.

Summary of the authentic picture

1. Yajuj and Majuj are already born and imprisoned behind Dhul-Qarnayn’s barrier.
2. When released after Jesus kills the Dajjal, they will swarm the earth in enormous numbers.
3. 999 out of every 1,000 humans sent to Hell will be from them (Bukhari/Muslim).
4. Allah will destroy them all in one morning with a plague/worm in their necks sent directly from Him — no human army kills them.

These are the hadiths accepted by mainstream Sunni scholarship (Ahl al-Sunnah wal-Jama‘ah).

Here are some of the most notable stories in the printed/medieval Book of Jasher (the 1840 English edition) that are clearly taken from rabbinic midrashim, Talmud, or later Jewish legendary sources — with the exact or near-exact sources:

Jasher Section / Story	Chapters in Jasher	Primary Midrashic / Talmudic / Medieval Source(s)
Adam and Eve after the expulsion: Cain and Abel born with twin sisters; the sisters fight over who marries whom → Cain kills Abel	1–2	Pirkei de-Rabbi Eliezer ch. 21; Bereshit Rabbah 22; Targum Pseudo-Jonathan Gen 4
The “Generations of the Heavens and Earth” — angels teach women cosmetics and sorcery → fallen angels (Watchers) story	2–3	1 Enoch 6–8 (but retold through Midrash Aggadah and Pirkei de-Rabbi Eliezer ch. 22)
Enoch taken to heaven, shown the tablets of heaven, made into Metatron-like figure	3	3 Enoch (Sefer Hekhalot), but filtered through later midrashim
Noah born shining white, speaks at birth, Lamech afraid he is from the angels	4–5	1 Enoch 106–107; Bereshit Rabbah 26; Pirkei de-Rabbi Eliezer 23
Detailed building of the ark, animals entering two-by-two and seven-by-seven exactly as God said	5–6	Pirkei de-Rabbi Eliezer ch. 23; Tanhuma Noah
Giants (Nephilim) in the earth, Og born before the Flood and survives by clinging to the ark	5 & later	Pirkei de-Rabbi Eliezer 23; Bavli Niddah 61a (Og survives Flood)
Abraham hidden in cave of Noah & Shem for first 10 years of his life	9–11	Pirkei de-Rabbi Eliezer ch. 26–27
Abraham smashes idols, thrown into Ur Kasdim furnace by Nimrod, survives 7 days	11–12	Bereshit Rabbah 38; Pirkei de-Rabbi Eliezer 26; Bavli Sanhedrin 109a
The raven sent from the ark brings food from Nimrod’s table (so it doesn’t return)	7	Pirkei de-Rabbi Eliezer ch. 23
Nimrod’s dream of a man rising from Abraham’s house who will overthrow him	11	Midrashic expansion; parallels in Louis Ginzberg’s Legends of the Jews
Abraham stays with Noah and Shem for 39 years and learns Torah	13	Pirkei de-Rabbi Eliezer 27; Sefer haYashar’s own chronology
The war of the four kings vs. five kings: full backstory, names of kings, Abraham trains 318 men with Eliezer	16	Bereshit Rabbah 42; Targum Pseudo-Jonathan Gen 14; Sefer haYashar expands heavily
Isaac’s birth: angels argue over who will have him as their “share”	18	Midrashic motif found in Yalkut Shimoni and later sources
The binding of Isaac (Akedah): Satan tries to stop Abraham, turns into river, etc.	22–23	Pirkei de-Rabbi Eliezer ch. 31; Tanhuma Vayera 22–23
Jacob and Esau: Esau sells birthright for red lentils because he killed Nimrod that day	26	Bereshit Rabbah 63; Targum Pseudo-Jonathan Gen 25; Midrash Sechel Tov
Jacob’s ladder: angels of Babylon, Greece, Rome ascend and fall	28	Slightly expanded from Bereshit Rabbah 68–69
Jacob in Laban’s house: detailed tricks with the rods, mandrakes, etc.	29–31	Pirkei de-Rabbi Eliezer 36–37; Midrashic expansions
Dinah and Shechem: Simeon and Levi use circumcision as a trick, kill all males	33–34	Midrash Sechel Tov; Tanhuma Vayishlach; Book of Jubilees 30 (very similar)
Joseph sold: Ishmaelites and Midianites both involved, long caravan description	42–44	Bereshit Rabbah 84; Tanhuma; Targum Pseudo-Jonathan Gen 37
Tamar and Judah: Tamar recognized by a “signet, cord, and staff” miracle	45	Midrashic expansions in Bereshit Rabbah 85
Moses raised in Pharaoh’s palace, flees after killing Egyptian, becomes king in Cush for 9 years, fights Balkis (Queen of Sheba’s mother)	70–77	Extremely famous medieval legend found in Sefer haYashar, Chronicles of Moses, Yalkut Shimoni, and Josephus Antiquities II (but greatly expanded)
The ten plagues: detailed magical duel between Moses/Aaron and Pharaoh’s magicians	79–80	Midrashic expansions in Shemot Rabbah and Tanhuma
Death of Pharaoh’s army: the sea splits into 12 paths, angels want to sing but God rebukes them	81	Mekhilta de-Rabbi Ishmael; Pirkei de-Rabbi Eliezer 42–43

Quick takeawayVirtually the entire Book of Jasher (Genesis through Joshua) is a giant medieval “midrashic novel.” It stitches together hundreds of stories from:

• Classical midrashim (Bereshit Rabbah, Shemot Rabbah, Tanhuma)
• Talmud (Bavli and Yerushalmi)
• Late midrashim (Pirkei de-Rabbi Eliezer, Midrash Tanhuma Buber)
• Medieval anthologies (Yalkut Shimoni, Chronicles of Jerahmeel)
• Earlier Second-Temple works (Jubilees, 1 Enoch fragments) filtered through rabbinic tradition

So if you love the dramatic extra details in the Book of Jasher, you’re basically reading a 16th–17th-century Jewish “greatest hits” collection of midrashic legends.

The Book of Jasher (Sefer haYashar) that is widely circulated today — the one printed in Hebrew in Venice 1625, translated into English in 1840 (Moses Samuel / Salt Lake City edition), and commonly sold as "The Book of Jasher" — is a medieval Jewish work (probably 16th–17th century, though some argue as early as 12th century in Naples). It is not the lost ancient Book of Jasher mentioned in Joshua 10:13 and 2 Samuel 1:18. The modern printed version is essentially a very expansive rewriting and harmonization of the entire Torah narrative (Genesis through Joshua) with huge amounts of extra detail.The Abraham section specificallyThe Abraham stories in this Book of Jasher (chapters 9–21 roughly) are dramatically expanded compared to Genesis and contain many famous legends that are not in the canonical Bible at all. Almost none of this material comes directly from the Apocrypha (the Deuterocanonical books accepted by Catholics/Orthodox). Instead, virtually all of it is drawn from much later Jewish sources, primarily:Main sources for the Abraham section in the printed Book of Jasher:

1. Midrashic and Talmudic traditions (especially):
   • Bereshit Rabbah (Genesis Rabbah) – major midrash on Genesis, 4th–6th century CE
   • Bavli Sanhedrin 109a–b (stories of Abraham smashed the idols, thrown into the furnace of Ur by Nimrod)
   • Bavli Bava Batra 91a, Pesahim 118a, etc.
   • Pirkei de-Rabbi Eliezer (8th–9th century) – huge influence; many episodes (Abraham in the furnace for 7 days, Haran’s death, Abraham hiding in the cave of Noah/Shem as a child, etc.) are lifted almost verbatim from PRE chapters 26–28.
2. Pseudepigrapha / Reworked Bible texts:
   • Jubilees (2nd century BCE) – some chronological and minor details (e.g., Abraham burning the idol temple, warning Terah), but Jasher is far more elaborate.
   • Apocalypse of Abraham (1st–2nd century CE) – almost no direct borrowing; the apocalyptic vision parts are very different.
   • Genesis Apocryphon (Dead Sea Scrolls, 1QapGen) – shares a few motifs (Abraham in Egypt, Sarah’s beauty), but again not a major source.
3. Later medieval midrashic compilations:
   • Sefer haYashar (the printed one) is especially close to Midrash Tadshe, Divrei haYamim shel Moshe, and especially Yalkut Shimoni (13th century anthology) on Genesis.
   • Chronicles of Jerahmeel (14th century) contains very similar Abraham legends and is sometimes suspected of being related or even a source/parallel.

Summary table of famous Abraham episodes in the printed Book of Jasher vs. their real origins

Episode in Jasher (chapters)	Primary source(s)	Found in Catholic/Orthodox Apocrypha?
Abraham born, hidden in cave for years (ch. 9–11)	Pirkei de-Rabbi Eliezer 26; Bereshit Rabbah 38	No
Abraham smashes Terah’s idols (ch. 11–12)	Bereshit Rabbah 38; Bavli Sanhedrin 109a; PRE 26	No
Nimrod throws Abraham into fiery furnace, Haran dies (ch. 12)	PRE 26; Bavli Pesahim 118a, Sanhedrin 109a; Midrash Tehillim	No
Abraham recognized by Nimrod’s servants by mark on his body (ch. 12)	Unique or late embellishment	No
Abraham teaches Noah/Shem, stays with them 39 years (ch. 13)	PRE 8, 27; Jubilees 11–12 (similar chronology)	No
Abraham burns the idol temple in Ur (ch. 13)	Jubilees 12:12–14; PRE 26 (less detailed)	No
Abraham in Canaan, fights the four kings with 318 men trained by Eliezer (ch. 16)	Genesis + midrashic expansion; some parallels in Josephus and Targums	No
Sarah taken by Pharaoh, plagues (ch. 15, 20)	Genesis 12 + 1QapGen (Genesis Apocryphon) + Sefer haYashar’s own expansion	No (1QapGen is not Apocrypha)

Bottom line

• Almost nothing in the Abraham section of the printed Book of Jasher comes from the Apocrypha (Tobit, Judith, Wisdom, Sirach, Baruch, Maccabees, etc.). Those books simply don’t contain Abraham legends.
• The material is overwhelmingly from classical and medieval rabbinic midrash (especially Pirkei de-Rabbi Eliezer and Bereshit Rabbah) and Second Temple/early post-biblical Jewish rewritings (Jubilees, Genesis Apocryphon), heavily embellished and harmonized by the medieval author/editor of the printed Sefer haYashar.

So when people read the dramatic Abraham stories in the modern “Book of Jasher,” they are reading medieval Jewish legendary expansion, not ancient lost scripture and definitely not from the Catholic/Orthodox Apocrypha.