Nahj al-Balāgha

Hadith 1182
governance
ومن خطبة له (عليه السلام) في شأن الحكمين وذمّ أهل الشام
About the two arbitrators (Abū Mūsā al-Ash‘arī and ‘Amr ibn al-‘Āṣ) and disparagement of the people of Syria (ash-Shām)
Source: al-Sharīf al-Raḍī