Musannaf Ibn Abi Shaybah

Hazrat Maymun bin Mehran narrates that Hazrat Ibn Umar (may Allah be pleased with them both) wrote a letter to Hazrat Umar, and he wrote as follows: From Abdullah bin Umar (may Allah be pleased with them both) to Umar. Hazrat Maymun said: Indeed, this is such a thing by which non-Arabs give preference to one another.