Because he knew Islam was un-inspired and would wither away if he could not exploit the talents and knowledge of those he conquered and attribute their product to Islam. Even today we justify the existence of this belief which should have been tossed on the dung heap of history because we mistakenly believe it had better days. And by golly, didn’t they invent the ZERO? (Not really.)
I read a book some time back on the history and concept of zero or nothing....
Islam really didn't invent the zero (in spite of what I learned in school)Islam got it from India... (at least per the book)
Zero, I thought it was the Assyrian Christians that came up with the concept?