Why is the city called a "Zonah"?
Rashi: She strays from her G-d.
Radak: A Zonah is not faithful to her husband. She lies to him and is Mezanah while married to him. So Yerushalayim, which was faithful to Kel in the days of David, Shlomo, Asa and Yehoshafat, when they did not offer on Bamos, only in the Mikdash, turned to be like a Zonah. They abandoned Beis Hashem, and offer on Bamos and to Asheros.
Malbim: The Navi depicts that a man saw Yerushalayim not long ago, in the ultimate Tzedek and Emunah. Now he comes and sees that they all converted to be evil to Hashem and to people. He asks how this happened so suddenly. A Tzadik does not become a Rasha so quickly! Perfection is in matters between man and his Maker, and Bein Adam l'Chavero. Regarding the former, the city of Emunah became like a Zonah who betrays the husband of her youth. Regarding the latter, they went from Tzedek to murderers!
What is "Mele'asi Mishpat"?
Rashi: It is full of judgment. The suffix Yud is extra, like "Rabasi Am" (Eichah 1:1). Radak - Yehoshafat established judges in all cities of Yehudah, and told them "Lo l'Adam Tishpetu Ki la'Shem", "v'Gam bi'Yrushalayim He'emid
Why does it say "Tzedek Yalin Bah"?
Rashi #1: The morning Tamid atones for sins of the night. The afternoon Tamid atones for sins of the day.
Rashi #2: They were Melin (left overnight) capital cases when they did not find reason to acquit during the day. They would not give the final verdict until the next day - perhaps they will find merit [to acquit him]. Now [the city] became murderers! Radak (citing Sanhedrin 35b) - i.e. now they finish capital cases the same day.
Radak: "Yalin" is not an expression of delaying overnight. Rather, it is diligence and constancy - "uv'Hamrosam Talan Eini", "uv'Otzaro Yalin Oz" (Iyov 17:2, 41:14). Tzedek was constantly in Yerushalayim!
Malbim: Last night, there was Tzedek in it. How can it be that on the coming night, murderers lodge in it?
