How Old Was Khadijah at Her Marriage?

The most widely repeated tradition, the one almost everyone knows, is that Khadijah رضي الله عنها was forty years old when she married the Prophet صلى الله عليه وسلم, who was twenty-five, and that she died at sixty-five. This figure comes from al-Wāqidī. The problem is that al-Wāqidī, though prolific, is significantly lower in scholarly reliability than the people who report the other figure.

Ibn Isḥāq, the earliest and most authoritative biographer of the Prophet صلى الله عليه وسلم, on whose Seerah all later scholars depend, says she was twenty-eight at the time of marriage. This is also reported by Hisām al-Kalbī. Al-Bayhaqi, another classical authority, records that she died when she was in her fifties (في الخمسينيات). If that is correct, and the marriage was at age twenty-eight, everything lines up.

The stronger argument is practical: Khadijah and the Prophet صلى الله عليه وسلم had at least six children together. A woman bearing six children across roughly twelve years, from the age of twenty-eight to forty, is entirely natural. A woman bearing six children beginning at the age of forty, in the seventh century, is extremely unlikely. This alone tips the balance toward twenty-eight.

What does not change is what matters most: she was older than him, had been married twice, and had a child. He chose her anyway, and remained faithful to her alone for twenty-five years, marrying no other wife until she had passed away. That fact, not the exact number of her years, is what speaks to his character.