TT #39 · Parashas Vayeira · Passuk 18:19
For I have known him, in order that he may command his children and his household after him to keep the way of Hashem by doing righteousness and justice, so that Hashem may bring upon Avraham that which He has spoken concerning him.
Torah Temimah points to Makkos 24a. E-Daf · Sefaria — Makkos 24a
TT lemma: צדקה ומשפט.
“Righteousness and justice.” Rabbi Simlai expounded: What is the meaning of the verse “He who walks in righteousness and speaks uprightly”? “He who walks in righteousness” refers to Avraham, as it is written of him, “For I have known him… to do righteousness and justice.”
Derash on the verse (Bavli sugya) — not a formal named middah of the 13. A later prophetic phrase is anchored in the description of Avraham.
Avraham is the model of “one who walks in righteousness”; the Torah itself describes him as commanding his household to practice tzedakah and mishpat.