It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Indeed, Allah, the Mighty and Majestic, dislikes for you excessive (boastful) eloquence."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7664