1)
Why will David never be ashamed?
1.
Malbim: It is because he returned to Yehudah via a Navi.
2)
Why did he say "b'Tzidkascha Faleteni"?
1.
Radak: Due to Your virtue, and not due to mine.
2.
Malbim: Even if I am not worthy based on my deeds, spare me amidst Tzedakah.
