Why did he say "Yadati Hashem"?
Malbim: I myself do not need [the good sign]. Even if great troubles beset me, I know that it is proper judgment for my sins. I have no doubt about Hashem's promise.
What is the meaning of "ve'Emunah Inisani"?
Rashi: You afflicted me [justifiably] in judgment. Radak - You are "Kel Emunah v'Ein Avel" (Devarim 32:4). "Ve'Emunah" is like uve'Emunah. Also "ha'Nimtza Veis Hashem" (Melachim II, 12:11, the prefix Beis is omitted).
Malbim: I know that You afflicted me to cleanse my sin and make me repent, in order to fulfill Your promise - "Asher b'Ha'avoso v'Hochachtiv b'Shevet Anashim" (Shmuel II, 7:14); "v'Chasdi Lo Afir me'Imo v'Lo Ashaker be'Emunasi" (above, 89:34).
