Critics allege that Aisha was just six years old when she was betrothed to Muhammad, himself in his 50s, and only nine when the marriage was consummated. They base this on a saying attributed to Aisha herself (Sahih Bukhari volume 5, book 58, number 234), and the debate on this issue is further complicated by the fact that some Muslims believe this to be a historically accurate account. Although most Muslims would not consider marrying off their nine-year-old daughters, those who accept this saying argue that since the Qur'an states that marriage is void unless entered into by consenting adults, Aisha must have entered puberty early.
They point out that, in seventh-century Arabia, adulthood was defined as the onset of puberty. (This much is true, and was also the case in Europe: five centuries after Muhammad's marriage to Aisha, 33-year-old King John of England married 12-year-old Isabella of Angoulême.) Interestingly, of the many criticisms of Muhammad made at the time by his opponents, none focused on Aisha's age at marriage.
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In addition, some modern Muslim scholars have more recently cast doubt on the veracity of the saying, or hadith, used to assert Aisha's young age. In Islam, the hadith literature (sayings of the prophet) is considered secondary to the Qur'an. While the Qur'an is considered to be the verbatim word of God, the hadiths were transmitted over time through a rigorous but not infallible methodology. Taking all known accounts and records of Aisha's age at marriage, estimates of her age range from nine to 19.
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The Islamophobic depiction of Muhammad's marriage to Aisha as motivated by misplaced desire fits within a broader Orientalist depiction of Muhammad as a philanderer. This idea dates back to the crusades. According to the academic Kecia Ali: "Accusations of lust and sensuality were a regular feature of medieval attacks on the prophet's character and, by extension, on the authenticity of Islam."