In all, the truth of the matter is this, king solon's wealth was not from israel alone, he had control over many cities and kingdoms that they had to bring him tax in time interval, he gets 25 tons of gold yearly from those subject kingdoms and his wisdom gave him influence over many kings and queens of his time and these rulers always come to pay homage to him and hear his wisdom, he also do mercgant business (tradinging animals and other goods)

I believe the Bible 100% but Mansa Musa is the wealthiest man to ever walk the surface of this earth.