Parsha Vayeira - Beresheit - Chapter 18 - Verse 10
As Sarah listens at the doorway of the tent, the angels are outside telling Avraham that she will conceive & have a baby. This is such a powerful verse and we have the opportunity to learn so many lessons from it.
When one does acts of chesed it is a prelude for greatness. Sarah & Avraham hurried to do for others and so they merited greatness because of it. We see more examples of others in Torah who merited greatness directly from their ability to be kind to others - Rivka, Yosef, Moshe.
It is mentioned in this verse that the tent is behind Avraham. This comes to teach us that he always positioned himself so that Sarah could hear him & benefit from his teachings. In the commentary the binyan av is that this is how Sarah became great. Because she was always open to listening, she was always learning from Avraham, and so she was always growing.
The importance of a Sh'miat Ha'ozen (the listening ear) as a tool for growth is reinforced in Mishlei - Chapter 15 – Verse 31. "The ear that listens to rebuke of life shall lodge among the wise." If you listen, you will grow. We never want to stop growing because growth means getting closer and more connected to Hashem.