There was a large Christian community in Najran. In 631 C.E., The Holy Prophet invited them to accept Islam. In response, they challenged the Holy Prophet to a Mubahila. The Mubahila was an ancient way of ascertaining the truth. In a religious contest, each of the disputing parties was required to take a solemn oath that they were right and true, and called on God to wreak His vengeance on them if they lied. It was believed that in such cases, the liar was visited by the wrath of God and was destroyed. The Holy Prophet accepted the challenge and asked the Christians of Najran to send a deputation to Madina.