Al-Adab Al-Mufrad #871

Ash-Sharid said, "The Prophet, may Allah bless him and grant him peace, asked me to recite the poetry of Umayya ibn Abi's-Salt and I recited it. The Messenger of Allah, may Allah bless him and grant him peace, began to say, 'Go on, go on!' until I had recited a hundred lines.' The Prophet said, 'If only he had become Muslim.'"