One day the Prophet Mohammad was performing the morning prayer in the mosque. An Arab aspirant of Islam was among others praying with the Prophet. Mohammad happened to recite a verse in the Koran about Pharaoh’s claim, I am your true God. Upon hearing this the Arab was seized with such wrath that he interrupted his prayer to shout:
The son-of-a-bitch braggart!
When the Prophet finished the prayer, his companions began to chide the Arab: Not only is your prayer no good because you interrupted it with extraneous words, but you used dirty language in the presence of God’s Prophet.
The Arab stood trembling with fear and embarrassment, whereupon Gabriel appeared and said to the Prophet:
God sends you salaam and wishes that these people stop chastising this simple Arab; indeed his sincere curse moved me more than many a pious rosary prayer.
From The Tale of the Reed Pipe, by Massud Farzan.