What is the meaning of "Derachai Siparti"?
Rashi: I told to You my needs and my sins, and You answered me.
Radak: This is like "Lev Adam Yechashev Darko." I.e. my desire and matters of my ways that I wanted to do many times, I told them in front of You - "va'Yish'al David ba'Shem."
Malbim: He already said "Achalai Yikonu Derachai Lishmor Chukecha" (5), that his ways and customs should not oppose guarding the Chukim. After, he blessed Hashem for hearing his Tefilah, and asked Him to teach to him His Chukim (12). Now he requests again, to know their reasons and secrets, for I told my ways and I saw that You will answer me, like You heard the above Tefilah.
How did Hashem answer him?
Radak: You answered what I asked You to teach to me Your Chukim, which are hidden, and only a Chacham can understand them. You gave to me a heart to understand their true secret.
Malbim: Refer to 119:26:1:3.
