Where he said the greatest name is
Two verses, from two different surahs.
اسْمُ اللَّهِ الأَعْظَمُ فِي هَاتَيْنِ الآيَتَيْنِِ
Ismu-Llāhi-l-aʿẓamu fī hātayni-l-āyatayn
“The greatest name of Allah is in these two verses.”
Al-Baqarah 2:163 and Āl ʿImrān 3:1 to 2.
Where this comes from
He then recited: and your God is one God, there is no god but He, the Merciful, the Compassionate. And the opening of Al ʿImran: Alif Lam Mim, Allah, there is no god but He, the Living, the Sustainer.
The full narration
Asma bint Yazid narrated that the Prophet (ﷺ) said:“Allah's greatest name is in these two Ayah: ‘And your deity is One deity, there is none who has the right to be worshipped but He, Ar-Raḥmān, Ar-Raḥīm.’ And the Opening of Al-`Imrān: ‘Alif. Lām. Mīm. Allah, None has the right to be worshipped but He, the Ever living, the Sustainer.’”
Source
Jāmiʿ at-Tirmidhī · 3478
- Ahmad Muhammad Shakir: Hasan
- Al-Albani: Hasan
- Bashar Awad Maarouf: Hasan Sahih
- Zubair Ali Zai: Isnaad Hasan