Sahih Bukhari | Volume 5 | Hadith Number 213

Um Habiba and Um Salama mentioned a church they had seen in Ethiopia and in the church there were pictures. When they told the Prophet of this, he said, "Those people are such that if a pious man amongst them died, they build a place of worship over his grave and paint these pictures in it. Those people will be Allah's worst creatures on the Day of Resurrection."