Rabbi, and Professor of religion and philosophy at the University of Toronto, David Novak on tzedakah, the word usually translated righteousness in Old and New Testaments:
Now dikaiosyne is the Septuagint’s rendering of the Hebrew tsedaqah.Tsedaqah primarily means what God does graciously for humans. Secondarily, it means the human response to God’s grace. Often that response is an act of imitatio Dei. (David Novak, Talking With Christians: Musings of A Jewish Theologian, pg. 53)