The Christians from Najran were able to hold their Christian church service in the Prophet’s Mosque
Sixty Christians from Najran came to Medina. They exchanged information about Christianity and Islam with the Prophet Muhammad. After long discussion, they made the decision that they wanted to remain Christians. They decided against Islam. As they then wanted to pray, the Prophet allowed them to pray and have their Christian church service in the Prophet’s Mosque in Medina. (Ibn Hisham, as-Sira, Edition Wustenfeld, Volume I (Goettingen 1858), p. 401-402).