Sahih Muslim
The Book of Prayers (Kitab Al-Salat)
Book Number: 004 / Hadith Number: 1077
'A'isha reported: They (some Companions of the Holy Prophet) were conversing with one another in the presence of the Messenger of Allah (may peace be upon him) (during his last) illness. Umm Salama and Umm Habiba made a mention of the church and then (the hadith was) narrated.