Why did David call himself "Oni v'Evyon"?
Rashi: Every "Oni v'Evyon" in Tehilim refers to Yisrael.
Radak #1: Even though he was king, he was considered poor because he constantly needed Hashem's help and salvation.
Radak #2: I am poor, i.e. I lack Kaparah of my sins.
Malbim: Refer to 40:18:2:5. My enemies constantly pursue me, and I am poor and weak compared to them.
What is the meaning of "Yachashav Li"?
Rashi: He should consider my poverty, and save me.
Radak #1: He should intend to benefit me, help me and save me at a time of affliction.
Radak #2: I should be esteemed and good in His eyes. This is like "Lo Chashav Enosh" (Yeshayah 33:8).
Seforno: He should join good intent to deed.
Malbim: Hashem considers me poor, and I have nothing of my own, only what I get via His salvation.
Why did he say "Elokai Atah"?
Seforno: I pray to You.
Why did he ask that Hashem not delay?
Seforno: The day is short, and there is much work for me to do.
Malbim: I need salvation, and I myself am weak.