H20
in some tribes it was normal to eat human flesh merely because it is cultural to them
If Muhammed was a man who preached the word of God, he should of refrained from abominations without the excuse of well "it's cultural, muhammed didn't know any better"
on top of that, have you never proven that such a practise was cultural, unless you have done that... this was and still is the decision of a lone pervert who accepted someone's daughter in order for that father to fall in (the rich and powerfull) muhammed's grace