1)
Why does it say "k'Chasdecha"?
1.
Radak: Do with me like You did with me many times.
2)
What is "k'Mishpatecha"?
1.
Radak: This is like Your good conduct (refer to 119:132:1:1) with Your Chasidim; You sustain them. Do so to me!
2.
Malbim: According to Din - either based on merit, or Your promise.
