Sahih Bukhari, Chapter: Prayers (Salat)

Um Salama told Allah's Apostle about a church which she had seen in Ethiopia and which was called Mariya. She told him about the pictures which she had seen in it. Allah's Apostle said, "If any righteous pious man dies amongst them, they would build a place of worship at his grave and make these pictures in it; they are the worst creatures in the sight of Allah."