As usual, Christian apologists got this accusation from Muslim scholars, who refer to the practice in their fatwas (legal rulings by Islamic scholars). The problem is that, whenever we link to a fatwa discussing the Islamic practice of thighing, Westernized Muslims complain to the fatwa site administrators, and the administrators then remove the fatwa. Once the fatwa is removed, Westernized Muslims accuse us of inventing the issue of thighing in order to attack Muhammad!
Just so there's no denying the fact that Muslim scholars issue such rulings, here's a screenshot of a fatwa on thighing that is still available at Islam Web (though it may be taken down once this article circulates):
But this won't convince Westernized Muslim apologists, who, despite their profound ignorance of their own sources, nevertheless believe that they know more about Islam than their scholars and jurists. They will settle for nothing less than a clear Qur'an statement declaring: "Thus saith Allah on the issue of thighing . . .," and even here they would simply reinterpret the passage!
For those of us who are more balanced in our approach and less obsessed with defending Muhammad at all costs, the Muslim sources provide abundant material on the issue of thighing. In order to avoid any accusations of deception, however, I will (1) limit myself to narrations that are available online for everyone to read, and (2) proceed step by step, showing carefully how Muslim scholars arrive at their conclusions.
First, we need to keep in mind that the Muslim sources do not use the word "thighing." Instead, they refer to a practice that is usually translated into English as "fondling" or "playing." The term is used of some sort of sexual practice with virgins and with women during menses (when sex is forbidden, according to Qur'an 2:222). Here are two examples (there are plenty more):
Sahih al-Bukhari, Volume 7, Number 17:Notice that Muhammad found the practice of "fondling" virgins preferable to sex with adult women.
Narrated Jabir bin 'Abdullah: When I got married, Allah's Apostle said to me, "What type of lady have you married?" I replied, "I have married a matron.' He said, "Why, don't you have a liking for the virgins and for fondling them?" Jabir also said: Allah's Apostle said, "Why didn't you marry a young girl so that you might play with her and she with you?" (Available online here.)
Sahih al-Bukhari, Volume 1, Number 298:
Narrated 'Aisha: The Prophet and I used to take a bath from a single pot while we were Junub. During the menses, he used to order me to put on an Izar (dress worn below the waist) and used to fondle me. While in Itikaf, he used to bring his head near me and I would wash it while I used to be in my periods (menses). (Available online here.)
Second, Muhammad used to do something that would leave semen on his clothes. Here are two narrations (again, there are plenty more):
Sahih al-Bukhari, Volume 1, Number 231:What was Muhammad doing that left semen all over his clothes? Since Muhammad condemned both masturbation and coitus interruptus (removing the penis from a woman before ejaculation), this leaves Westernized Muslim apologists to argue that Muhammad's semen marks were the result of nocturnal emissions (wet dreams). But Muhammad had far, far too much sex to have nocturnal emissions.
Narrated Sulaiman bin Yasar: I asked 'Aisha about the clothes soiled with semen. She replied, "I used to wash it off the clothes of Allah's Apostle and he would go for the prayer while water spots were still visible." (Available online here.)
Sahih al-Bukhari, Volume 1, Number 233:
Narrated 'Aisha: I used to wash the semen off the clothes of the Prophet and even then I used to notice one or more spots on them. (Available online here.)
Sahih al-Bukhari Volume 1, Number 268: Narrated Qatada: Anas bin Malik said, "The Prophet used to visit all his wives in a round, during the day and night and they were eleven in number." I asked Anas, "Had the Prophet the strength for it?" Anas replied, "We used to say that the Prophet was given the strength of thirty (men)." And Sa'id said on the authority of Qatada that Anas had told him about nine wives only (not eleven). (Available online here.)Even with so many wives, Muhammad got in trouble for having sex with his slave-girl, Mary the Copt.
Sahih al-Bukhari Volume 7, Number 142: Narrated Anas bin Malik: The Prophet used to pass by (have sexual relation with) all his wives in one night, and at that time he had nine wives. (Available online here.)
So the semen on Muhammad's clothes didn't result from masturbation, coitus interruptus, or nocturnal emissions. Via the process of elimination, that leaves us with some sort of sexual practice with his wives, which didn't involve masturbation, but also didn't involve penetration. Hence, Muhammad must have been using his wives' bodies to pleasure himself. Apart from penetration, how did Muhammad use his wives' bodies to satisfy his sexual urges? Muslim scholars have a simple answer that explains all of the data: Muhammad practiced "thighing."
Moreover, since Muhammad found the practice of thighing virgins preferable to sex with grown women (as we saw in Sahih al-Bukhari), he must have had some experience with thighing virgins. Muhammad married Aisha when she was six years old, but didn't consummate the marriage until she was nine years old. This three-year period between marriage and consummation must have been the time when he practiced thighing (unless our Muslim friends want to argue that he practiced thighing with a different virgin).
Of course, if Westernized Muslim apologists want to argue that Muhammad didn't practice thighing, they're free to explain the data in some other way. They merely need to tell us (a) what the practice of "fondling" involved, (b) what Muhammad was doing that left semen all over his clothes, and (c) why Muslim scholars have concluded that Muhammad practiced thighing. If they can explain these issues successfully, I suppose we'll have to drop the issue of thighing.
In the meantime, it's a bit disingenuous for Westernized Muslim apologists to accuse us of deception, when we only started drawing attention to "thighing" because Muslim scholars were talking about it. When we factor in the evidence from the Hadith, which is entirely consistent with thighing and inexplicable without it, we can only conclude that Muslim scholars who describe this early Islamic practice are absolutely correct.
Alternatively, Westernized Muslim apologists might want to take an indirect approach, by arguing that Muhammad couldn't have practiced thighing, since Muhammad is the pattern of conduct for all men (Qur'an 33:21), and "thighing" a little girl obviously isn't something that Islam's highest pattern of conduct would do. But let's face it. Muhammad (1) had sex with a prepubescent girl, (2) had sex with nearly a dozen women in one day, (3) had sex with his slave-girl in his wife's bed, (4) married the divorced wife of his own adopted son, (5) married a woman after having her husband tortured and killed, (6) allowed his followers to rape their female captives, (7) allowed his followers to hire prostitutes, and (8) promised his followers a paradise of eternal erections, which they will use to endlessly deflower their virgins. If Muslims want to argue that a man who did and taught all of this simply couldn't put his penis between his child-bride's legs, we'll have to wait patiently for their proof.