The movie never explains Moses' (Momo) father's indifference to his son, the absent (fantasy?) older brother, the abandoning mother, or Monsieur Ibrahim's friendship to Momo.
Monsieur Ibrahim kept saying, "I know what is in my Koran." When Ibrahim dies and his lawyer reads the will which leaves the Koran to Momo, I expected Momo to open the book and find an intimate photo of Monsieur Ibrahim with Momo's mother. That would have explained everything.
As written, there is not much point to the story.