Hadith
حَدَّثَنِي مَالِكٌ، عَنْ زَيْدِ بْنِ أَسْلَمَ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّهُ قَالَ قَدِمَ رَجُلاَنِ مِنَ الْمَشْرِقِ فَخَطَبَا فَعَجِبَ النَّاسُ لِبَيَانِهِمَا فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنَّ مِنَ الْبَيَانِ لَسِحْرًا " . أَوْ قَالَ " إِنَّ بَعْضَ الْبَيَانِ لَسِحْرٌ " .
Malik related to me from Zayd ibn Aslam that Abdullah ibn Umar said, "Two men from the east stood up and spoke, and people were amazed at their eloquence. The Messenger of Allah, may Allah bless him and grant him peace, said, 'Some eloquence is sorcery,' or he said, 'Part of eloquence is sorcery
Sahih · Salim al-Hilali
Muwatta Malik 1817 ·Book 56, Hadith 7·Also available on sunnah.com·