John Calvin Commentary Genesis 30:43

"And the man increased exceedingly, and had large flocks, and maid-servants and men-servants, and camels and asses." — Genesis 30:43 (ASV)

And the man increased exceedingly. Moses added this to show that he was not made so suddenly rich without a miracle. We will see later how great his wealth was. For though he was entirely destitute, he still gathered from nothing greater riches than any man of moderate wealth could accumulate in twenty or thirty years. And so that no one would consider this unbelievable, as it was not according to the usual method, Moses addresses the objection by stating that the holy man was enriched in an extraordinary way.