the prophet of islam muhammad married Khadijah a 40 years old very rich woman when he was 25 , she was 15 years older than him
he didn't have a harem or 13 wives he didn't dare to have a harem since his wife was the one with the money , the person giving him his allowance , she was his work boss , now after her death muhammad inherited her money and he's 50 years old
so he built his own harem including a 9 years old kid -aisha-
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that the Prophet (ﷺ) married her when she was six years old and he consummated his marriage when she was nine years old. Hisham said: I have been informed that `Aisha remained with the Prophet (ﷺ) for nine years (i.e. till his death).
Authentic Hadith
Reference : Sahih al-Bukhari 5134
In-book reference : Book 67, Hadith 70
USC-MSA web (English) reference : Vol. 7, Book 62, Hadith 65
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in case you don't know being mentioned in sahih al bukhari means that any muslim that say it's wrong hadith will be leaving islam and becomming apostate or kaffer
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why didn't muhammad married a 9 years old kid bacck when he was with 15 years older woman than him ? the answer is simple he didn't dare since he was digging gold from her