Why does it say "Od Bikshah Nafshi"?
Rashi: Aside from what I said above that I sought and did not find 1 , I sought a Kosher woman.
Rashbam: I sought people complete in their deeds.
Seforno: I sought in old Seforim to find how many people, this did not happen to them [that one Aveirah leads to another].
Metzudas David: I sought something else abnormal - to find something without comparing it to its opposite.
Ri Kara: Seder of the world, what is above and below [this world].
What is the significance of finding one man among 1,000?
Rashi citing Koheles Rabah: Normally, if 1,000 enter to learn Mikra, only 100 come out proper to learn Mishnah. Of them, only 10 come out proper to learn Talmud, and only one of them succeeds.
Ri Kara: One out of 1,000 is faithful in his deeds and speech.
Seforno: One out of 1,000 repented from his sin, and did not sin a second time.
Metzudas David: One out of 1,000 men is intrinsically straight; he need not be compared to others.
What is "b'Chol Eleh"?
Rashbam: Of the 1000 mentioned [regarding men]. Ibn Ezra, Metzudas David - Shlomo had this many women - 700 wives and 300 Pilagshim (Melachim I, 11:3).
Why did he not find any woman?
Rashi: He did not find a Kosher woman, for Daitan Kalos (they are easily distracted). Therefore, you must beware of women!
Rid: I sought a totally good woman, and did not find one.
Seforno: I did not find one who repented from her sin, and did not sin a second time.
Metzudas David: None was intrinsically straight and proper.