Parsha Vayeira - Beresheit - Chapter 18 - Verse 17-19
In performing acts of chesed, Avraham Avinu demonstrated by example how we are to behave in the world, how loving-kindness is to imbue our actions and behavior each day of our lives. These acts of kindness were not performed by Avraham just when the need “revealed itself.” Rather, Avraham’s actions teach us that a true ba’al chesed actively seeks out for the opportunity to perform acts of loving-kindness.
In the verses we discuss today Hashem gives Avraham a greater opportunity to go even farther in the depth of his kindness, as he reveals his decision to destroy Sodom. This gives Avraham the opportunity to daven for them. In that we see Avraham's rachmonos/rachmanut, (mercy/compassion). It shows us he is not just doing a chesed but, thinking about the feelings of the other person. A rachmoni is someone who has mercy.
This is a prelude for Avraham's mission statement which is in Verse 19. Hashem says, Avraham and I are in sync & intimately connected. Avraham knows me, knows my will & what I want, so he is the perfect person to carry on my mission and teach it to his children and their future generations will merit receiving the Torah.