Shama-il Tirmidhi Chapter 036, Hadith Number 008 (238).

Amr ibn Shareed radiyallahu anhu reports that his father said, I once accompanied Rasoolullah sallallahu alaihe wasallam and sat behind him on a conveyance. I recited a hundred couplets of Umayyah ibn Sault to Rasoolullah sallallahu alaihe wasallam. After reciting a couplet Rasoolullah sallallahu alaihe wasallam said ‘continue’ till I recited a hundred couplets. In the end Rasoolullah sallallahu alaihe wasallam said, ‘He (Umayyah) was close to accepting Islam.

Commentary
The reason for this has already been mentioned. In his poetry Umayyah mostly mentioned the tauheed (the oneness of Allah), the hereafter, advice and the truth. For this reason Sayyidina Rasoolullah sallallahu alaihe wasallam listened to his poetry and said that he was near to accepting Islam. Some of the Ulama have said that Sayyidina Rasoolullah sallallahu alaihe wasallam said this on the couplet, ‘O’ our Lord, all praises, affluence and superiority is only for You. None is more worthy of praises, nor greatness besides You.’