Sayyidah Aishah (may Allah be pleased with her) said: The Messenger of Allah (peace and blessings be upon him) never composed a single line of poetry except one line: "Take a good omen in what you desire and it will be; for seldom is it said of a thing 'it has happened' except that it comes true." Sayyidah Aishah (may Allah be pleased with her) said: He did not say 'tahaqquqa', so as not to give it its (metrical) ending and so make it poetry.
The Shaykh (Imam al-Bayhaqi) (may Allah have mercy on him) said: I have recorded it only with this chain, and among its narrators is one whose condition is unknown. As for rajaz, the Messenger of Allah (peace and blessings be upon him) used to recite it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13291