People find it easy to criticize Sarai and Abram for their impatience in waiting for the son God promised them, but our insight is simply nothing more than hindsight. We aren’t any smarter or more faithful to God than they were.
Apostle Paul used as illustrations the two women, Sarai and Hagar, and the covenants God made with their sons, Isaac and Ishmael. Once you transgress a covenant, you have no hope, unless Someone better than you steps in with a second, better covenant.