Hadith: I will certainly expel the Jews and the Christians from the Arabian Peninsula until only Muslims are left in it

عن عمر بن الخطاب أنه سمع رسول الله صلى الله عليه وسلم يقول: «لأُخْرِجَنَّ اليهودَ والنصارى مِن جَزِيرة العرب حتى لا أدَعَ إلا مُسلما».
[صحيح] - [رواه مسلم]

‘Umar ibn al-Khattāb (may Allah be pleased with him) reported that he heard the Messenger of Allah (may Allah’s peace and blessings be upon him) say: "I will certainly expel the Jews and the Christians from the Arabian Peninsula until only Muslims are left in it."
Sahih/Authentic. - [Muslim]

Explanation

In this Hadīth, ‘Umar (may Allah be pleased with him) tells about the Prophet's determination to expel the Jews and Christians from the Arabian Peninsula so that there would not be two religions in the Peninsula and to keep it ever redolent of monotheism, with no trace of polytheism. That is because living near the disbelievers and socializing with them entail great evils, including the possibility of imitating them, admiring their beliefs, or assuming their mannerisms by the naive and gullible Muslims. Muslims must be distinguished and independent in their own homeland, and they should not mix with followers of the other religions. Hence, the Jews, Christians, Magi, and other disbelievers must be driven out of the Arabian Peninsula, which is exclusively for the Muslims. The Arabs are the first nation to receive the message of Muhammad (may Allah's peace and blessings be upon him) and their homeland is the place where revelation came down. Therefore, non-Muslims should never reside therein.