Mary’s faithfulness is witnessed her entire life and is most eloquently understood with the phrase “kept them in her heart” in reference to incidences in her life as Christ’s mother. It is faith - fully alive within our hearts - that keeps company with those things we don’t understand but desire to use in our own purposeful walk with the Lord.
Rachel, too, kept things hidden in her heart where she pondered them, trying to make sense of them - using them to fulfill her role as a Matriarch. Rachel tapped into her heartache - arising from a desire for motherhood - to learn about faith. Rachel died giving birth to her second son, Benjamin.
Rachel shows, as does Mary, that to keep things in our heart and ponder how they are part of our journey requires a significant amount of faith. Faith, then, resides with these things in our heart, allowing wisdom to be gained from them.