Why does it say "Az Tikra va'Shem Ya'aneh"?
Rashi: Now, when you do evil deeds, you say "we fasted and You did not see" (3). When you will improve your ways, you will know that I will answer you when you call, and I will see your fast and hear your prayer.
Malbim: Even not at a time of affliction, you will call and He will answer.
What is the significance of "Teshava va'Yomar Hineni"?
Malbim: If you will cry out at a time of affliction, not only will I answer you - I will also say, I was prepared to save you even before you cried out!
Who receives this Brachah?
Yevamos 63a: It is for one who loves his neighbors, draws his relatives close, marries his sister's daughter, and lends to an Oni when he needs it 1 .
Rashi (63a): Verse 7 mentioned "umi'Besarcha Lo Sis'alem" (loving neighbors, who are like relative) - he brings his relatives close and marries his sister's daughter, "Ki Sir'eh Arum v'Chisiso" (he helps an Oni in need).
What should be removed?
Radak: You should repent from these evil deeds, and do good deeds.
What is the significance of "Shelach Etzba"?
Radak: Shelach is Makor (like an infinitive), like it says above "Lehakos b'Egrof Resha" (4). When people fight, often one sticks his finger in the other's face, without hitting him - you should cease even this.
Malbim: Do not send even a finger for evil, and all the more so not the entire hand.
What is "Devar Aven"?
Radak: Do not quarrel even verbally. All of these are included in "Chartzuvos Resha" (6).
Malbim: Do not even speak of sin.