Why did God decide to let Abraham in on the destruction of Sodom? The Targum answers with one Aramaic word: chasidutha — piety, devotion, loving-kindness. His chasidut, the Targum says, "is manifest before Me" (Genesis 18:19).
But then the verse turns immediately from Abraham's character to his curriculum. He will instruct his sons, and the men of his house after him, to keep the ways that are right before the Lord, to do justice and judgment. Chasidut alone is not what earned the disclosure. Chasidut plus transmission did.
Targum Pseudo-Jonathan is making a sharp claim about what kind of righteous person actually moves the heavens. It is not the mystic alone in his tent. It is the teacher. The patriarch who takes his household aside and drills them on what justice looks like when no one is watching. Abraham's chesed is contagious. That is why God commits to bringing upon him "that which He hath spoken" — the promise of a great nation.
The rabbis consistently read this verse as the template for Jewish parenting. Not: raise children who feel holy. Rather: raise children who know the difference between tzedek (righteousness) and mishpat (judgment), and who can do both, in the street, in court, at the table.
The takeaway is blunt. Private piety expires with the person who practiced it. Piety you transmit becomes a nation.