1)
Why does it say "Chilah"?
1.
Ba'al ha'Turim: The only other place it says so is Devarim 29:31, "Asher Chilah Hashem Bah." Just like there, it is breaking the land, also here, Hashem dug an opening for him under Kisei ha'Kavod to accept his Teshuvah.
2.
Malbim: Chilah is to remove anger. Tefilah (verse 13) is to obtain desire (that Hashem will want to help him).
