Why did Hashem choose Avraham?

It’s not really a mystery: God tells us Himself in this week’s torah portion. As Hashem says “because I know him, since he will command his children and his household after him and they will keep the path of Hashem, to do righteousness and justice.”

Yet, we may struggle to find an instance where this actually occurred! When does Avraham teach his children what to do?