How did Jacob marry 2 sisters?

Our ancestor Jacob was tricked by his uncle Laban into marrying Laban's 2 daughters Rachel and Leah. While the Torah allows for polygamy, it does not allow for marrying two sisters. How then was Jacob able to marry two sisters in violation of Jewish law? This classic question has been asked and addressed by countless commentaries over our long history.  A fascinating discussion addressing this classic question of how Jacob could have married two sisters.