Namaa Community at IslamicEval 2026: Retrieval-Grounded Verification of Qur’anic and Hadith Citations for Hallucination Identification

Fatimah Mohamed Emad Elden, Israa Elhosiny, Khloud Al Jallad, Omer Nacar


Abstract
Large language models may generate inaccurate Islamic citations when answering religious questions. We present the Namaa Community system for Subtask 2 of IslamicEval 2026, which identifies hallucinations in Qur’anic verses (Ayah), hadith texts (matn), chains of narration (isnad), and claimed sources. We formulate the task as retrieval-grounded verification: citation spans are normalized and matched against the Qur’an and the six major hadith collections using character n-gram retrieval and edit-distance re-ranking. Type-specific verifiers assess Ayah and matn similarity, while claimed sources and isnads are checked against their parent citations. The deterministic pipeline requires no language model or GPU, and every decision is traceable to a canonical record. It achieves a macro accuracy of 0.846 on the development set, 17.9 percentage points above a per-type majority-class baseline, and 0.668 on the official blind test; we trace most of that shortfall to a submission-time configuration error and decompose the remainder by segment type. Our code and submissions are publicly available at https://github.com/NAMAA-ORG/Namaa-Community-at-IslamicEval-2026.
Anthology ID:
2026.arabicnlp-sharedtasks.136
Volume:
Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Muhammad Abdul-Mageed, Tamer Elsayed, Houda Bouamor, Samhaa El-Beltagy, Hend Al-Khalifa, Ahmed Abdelali, AbdelRahim Elmadany, Abdellah El Mekki, Kareem Darwish, Sakhar Alkhereyf, Hamzah Luqman, Salam Khalifa, Samar Magdy, Zaid Alyafeai, Injy Hamed, Wajdi Zaghouani, Imed Zitouni
Venue:
ArabicNLP
SIG:
SIGARAB
Publisher:
Association for Computational Linguistics
Note:
Pages:
1098–1105
Language:
URL:
https://aclanthology.org/2026.arabicnlp-sharedtasks.136/
DOI:
Bibkey:
Cite (ACL):
Fatimah Mohamed Emad Elden, Israa Elhosiny, Khloud Al Jallad, and Omer Nacar. 2026. Namaa Community at IslamicEval 2026: Retrieval-Grounded Verification of Qur’anic and Hadith Citations for Hallucination Identification. In Proceedings of The Fourth Arabic Natural Language Processing Conference: Shared Tasks, pages 1098–1105, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Namaa Community at IslamicEval 2026: Retrieval-Grounded Verification of Qur’anic and Hadith Citations for Hallucination Identification (Mohamed Emad Elden et al., ArabicNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.arabicnlp-sharedtasks.136.pdf