At Muslims and Muhammad: the Impossible Task, I posted, "It is impossible that a man could sentence a woman to death by having her limbs attached to camels that moved in opposite direction pulling her apart, then behead her and parade her severed head through Medina, and be a prophet of God."
The story of Umm Qirfa has been dramatized at this link. For the historian, what is of significance is not the dramatization of her death, but its documentation in Islamic history.
In a lengthy account of all the raids led or ordered by Muhammad, historian Ibn Ishaq reports that the Prophet sent a force led by Zayd bin Haritha against the Beni Fazara tribe. It is interesting that Ibn Ishaq now describes Zayd as "the freed slave" of Muhammad; earlier in his book he had identified Zayd as "Zayd bin Muhammad", or Zayd the son of Muhammad. This changed when Muhammad claimed he had received a revelation making adoption illegal so he could marry Zayd's wife Zainab and adopted sons could no longer carry the names of their adopted fathers. At any rate, some of Zayd's soldiers were killed in the battle and he himself was wounded and carried from the field. Zayd swore he would not rest until he had gained revenge on the Beni Fazara, and as soon as he recovered from his wounds he again attacked them. This time he was successful and killed or captured the members of the tribe. One of the prisoners, described by Ibn Ishaq as "a very old woman", was Umm Qirfa whose family led the tribe. Ibn Ishaq limits himself to saying that "Zayd ordered Qays to kill Umm Qirfa, and he killed her cruelly". Historian al-Tabari adds the detail that "Qays put a rope to her two legs and to two camels, and drove them apart until they tore her apart". Muslim historian Kamel Najar informs us that Umm Qirfa's head was presented to Muhammad, who ordered it to be paraded throughout Medina.
A Muslim warrior named Salama took the beautiful daughter of Umm Qirfa as a captive. When Muhammad saw her, he asked Salama to give the girl to Muhammad's uncle Hazan. Hazan then "married" her and she gave birth to a son.
There are numerous other examples in Muhammad's life where wantom cruelty was expended on his enemies. One such account is given by a man named Amr bin Umayya, who was sent by Muhammad to kill arch-enemy Abu Sufyan before Abu Sufyan himself became a Muslim and subsequent leader of the Muslim armies. Amr and his companion tried to approach Abu Sufyan's house in Mecca, but were recognized and forced to flee for their lives with their Meccan pursuers close behind. They made their way back to Medina travelling by day and spending the nights in caves. Ibn Ishaq continues the account with Amr speaking as follows:
I went into a cave, and while I was there a one-eyed man also came into the cave with a sheep of his and asked me who I was. When we discovered we were from the same tribe, he laid down and began to sing, "I will not become a Muslim as long as I live." I said to myself, "I'll teach you", and as soon as he fell asleep I got up and killed him in a more horrible way than any man has been killed. I put the end of my bow in his one eye, and pushed it down until it came out at the back of his neck. After I left the cave, I came across two Meccans whom the Quraysh had sent to spy on the Apostle. I killed one of them, and bound the thumbs of the other together with my bow string and took him to the Apostle. When the Apostle looked at him, he laughed so hard you could see his back teeth. He asked my news, and when I told him what had happened he blessed me.
Another well-known incident of cruelty occured during Muhammad's raid upon the Jews of Khaybar. Believing that a young man named Kinana had access to hidden treasure, Ibn Ishaq writes: The Apostle asked Kinana where the rest of the treasure was, but he refused to produce it. The Apostle then gave the order to Zubayr to torture him until they extracted what he had. Zubayr kindled a fire with flint and steel on his chest until he was nearly dead. Then the Apostle delivered him to Muhammad bin Maslama, who cut off his head.
Still another incident is contained in the authoritative Bukhari collection of Hadiths. A group of eight men from the Ukil tribe came to Medina and professed to accept Islam. When they complained to Muhammad that Medina's climate was not good for them, Muhammad advised them to join the city's camel herders so they could regain their health by drinking an abundance of fresh camel milk. The men followed his advice but then murdered a herder, stole his camels and fled. Muhammad quickly pursued and captured them, and in punishment cut off their hands and feet, branded out their eyes with hot nails, and left them to die without water in the desert outside Medina.
There are some Muslims who recognize that these stories are troublesome. On an Egyptian talk show a few years ago one participant noted that militant Muslims such as the late Abu-Musab al-Zarqawi justified the beheading of journalist Daniel Pearl because Muhammad himself beheaded people. The participant then said, "The problem is that the Ulema (Islamic scholars) have no answer for the militants who base their violence on Muhammad's actions. When these people say that Muhammad himself branded and plucked out the eyes of the thieves and cut off their hands and legs, what is the response (of the Ulema)? And this is what Muhammad did in some small peacetime conflict. What would he do in war?"
It's a good question, and one that can be answered by seeing what Muhammad's followers do to each other, let alone to the enemy, in places such as Baghdad where for months the Shia Jaysh al-Mahdi would bind the hands of their Sunni enemies behind their backs before drilling holes into their skulls, shooting them in the back, and dumping their bodies into the streets. It doesn't take much analysis to understand how they justify their actions based on the example of their Prophet.
I can't do that. It is impossible to me that a man who would treat his opponents with the cruelty that Muhammad did could possibly be a prophet of God.