“who resides in the midst of her.” Yahweh was in His Temple in the midst of Jerusalem.
“is righteous.” That is, God treats people with justice and equity (see commentary on Matt. 5:6).
“Morning by morning.” Although this is a general phrase meaning “over and over,” it was chosen on purpose to highlight the justice and love of God, because every morning, morning after morning, the priests offer the morning sacrifice in the Temple and portray how God cares for people and atones for people’s sin.
“an unjust person knows no shame.” In the honor-shame society of the biblical world, and still in the east and Middle East today, concern about “shame” (sometimes referred to as “losing face” in Asia) is very real, and avoiding shame and being honored is very important to people and a huge motivator to behave according to societal standards. But these unjust people were so committed to their sin and had such hard hearts that they did not experience (“know”) any shame over their horrendous acts against God and other people. They refused correction and so to protect other people from them God’s only course of action was to act powerfully against them. That situation is still true today, and is why laws must be enforced by police in today’s society and why death in the Lake of Fire is God’s righteous action against willful evil (Rev. 20:11-15).