Al-Kāfi

Hadith 185
سَهْلٌ عَنِ الْحَسَنِ بْنِ مَحْبُوبٍ عَنْ حَنَانٍ عَنْ زُرَارَةَ قَالَ قَالَ أَبُو عَبْدِ اللَّهِ (عليه السلام) نَحْنُ قُرَيْشٌ وَ شِيعَتُنَا الْعَرَبُ وَ سَائِرُ النَّاسِ عُلُوجُ الرُّومِ.
184. Sahl, from Al-Hassan Bin Mahboub, from Hanaan, from Zurara who said: Abu Abdullah (asws) said: ‘We (asws) are Quraysh, and our (asws) Shiites are the Arabs, and the rest of the people are Romans.
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī