Sources & Method

Sources

The Arabic Quran text and surah/juz/page data come from the Tanzil Project (tanzil.net) — openly licensed, used unmodified, with attribution.

Translations: Turkish by Elmalılı Hamdi Yazır (public domain), English by M. M. Pickthall (public domain), German by Bubenheim & Elyas (via Tanzil, under non-commercial terms) — all three via Tanzil's digital edition.

Tafsirs

Tafsir texts come from the OpenITI Corpus (openiti.org) — an academic open-access project digitizing classical Islamic texts. License: CC BY-NC-SA 4.0, non-commercial use only. That's why TafsirPrism is currently donation-supported/free.

• al-Tabari — Jami al-Bayan (9th-10th c.)
• al-Zamakhshari — al-Kashshaf (12th c.)
• Fakhr al-Din al-Razi — Mafatih al-Ghayb (12th-13th c.)
• al-Qurtubi — al-Jami li-Ahkam al-Quran (13th c.)
• Ibn Kathir — Tafsir al-Quran al-Azim (14th c.)
• al-Baydawi — Anwar al-Tanzil wa Asrar al-Ta'wil (13th c.)

Abu al-Su'ud and Elmalılı will be added later. Some tafsir sources (e.g. altafsir.com's own digital collection) were deliberately not used because they would have violated that site's terms of use.

Occasion of Revelation (Asbab al-Nuzul)

On verse pages, before the tafsir comparison, we show a classical narration of the historical occasion or question behind that verse's revelation. This differs from the tafsirs' interpretation of the verse's content — here only the occasion/context is conveyed, with no ruling or interpretation added.

• al-Wahidi — Asbab al-Nuzul (d. 468 AH)
• as-Suyuti — Lubab al-Nuqul fi Asbab al-Nuzul (d. 911 AH)

Both come from the OpenITI Corpus under the same CC BY-NC-SA 4.0 license as the tafsirs. These classical works don't cover every verse of the Quran, only those with a documented occasion of revelation — so this section is absent on most verses, which is expected and not a data gap. The narration texts are translated directly from the Arabic original into Turkish, German, and English (the Arabic always remains visible); currently Surat al-Fath (48), Surat Ya-Sin (36), Surat Al Imran (3), and Surat al-Baqara (2) have been processed, with other surahs to follow in stages.

How does the AI work?

1. Retrieve: Passages from each tafsir are located for the relevant verse.
2. Summarize: For each tafsir separately — a view, its basis, and a verbatim quote are produced.
3. Verify: Is the generated quote really a verbatim match in the source text — checked in code. If not, it's rejected; the model isn't trusted blindly.
4. Compare: Built only from verified summaries — common ground, differences, historical context.
5. Modern connection: Written cautiously, without claiming a final conclusion.
6. Safety filter: If absolute language or sensitive topics are detected, the content goes to human review.