He was a painstaking jurist and an exceptionally forceful, eloquent preacher. People still speak of the famous day on which he filled every ear and dazzled every mind. The story goes that al-Mustansir bi-Allah was enamored of Abū ʿAlī al-Qālī and would assign him every important task. When the Byzantine envoy arrived, the caliph ordered Abū ʿAlī—as was the custom—to mount the pulpit and deliver the sermon. But the sight of the vast crowd unnerved Abū ʿAlī: his legs would not carry him and his tongue failed him. Mundhir ibn Saʿīd noticed what had happened, sprang forward on the spot, took Abū ʿAlī’s place, and improvised a magnificent sermon that left the audience speechless. At its close he recited, as his own poetry:
This discourse has no flaw that faulty words could expose,
Yet its speaker has been belittled by this town.
Had I been a stranger among them, I would have stood out in splendor;
Because I am one of them, ill fortune has struck me down.
Were it not for the caliphate—may Allah preserve its radiance—
I would never stay in a land where not a single worthy man remains.
The listeners were delighted. The envoy made the sign of the cross and said, “This man is the champion ram of the state’s men.” (1)

Among his written works are Kitāb al-Inbāh ʿan al-Aḥkām min Kitāb Allah (The Alert to the Rulings Drawn from the Book of Allah) and Kitāb al-Ibānah ʿan Ḥaqāʾiq Uṣūl al-Diyānah (The Clarification of the Realities of the Principles of the Religion).

Ibn Bashkuwāl writes in one of his books: “Mundhir ibn Saʿīd was an eloquent, commanding preacher (2); in al-Andalus none could surpass him on the pulpit. He combined outstanding scholarship, comprehensive knowledge, unshakeable certainty in the sciences and the religion, devout piety, abundant fasting, regular night prayer, and fearless proclamation of the truth. No blame in the way of Allah ever deterred him. He prayed for rain on more than one occasion, and each time rain was sent.

He mentioned the Commander of the Faithful al-Ḥakam, saying, ‘He was a jurist, articulate, an accomplished orator…’