Musannaf Ibn Abi Shayba 3:1972

Affan narrated to us, he said: Hammad bin Salamah narrated to us, from Ali bin Zayd, from Yusuf bin Mahran, from Ibn Abbas, from Ali, he said: The *aza'im* (obligatory/firm) prostrations of the Quran are: *Alif Lam Mim Tanzil* (Surah As-Sajdah), *Ha Mim Tanzil* (Surah Fussilat), *An-Najm*, and *Iqra' bismi Rabbika alladhi khalaq* (Surah Al-Alaq).