Why does it say "Lachen Ko E'eseh Lecha Yisrael"?
Rashi: Because you did not repent to Me, I will do to you all these evils.
Malbim: After it says "Im Yitaka Shofar ba'Ir v'Am Lo Yecheradu" and "Im Tihyeh Ra'ah b1a'Ir va'Shem Lo Asah" (3:6), He clarified to them that all these evils are not chance, rather, due to Hashgachah, via their sins. Now it explains "Lo Ya'aseh Hashem... Ki Im Galah Sodo" (3:7). Hashem does not do evil absolutely. He decrees evil in order that they will repent via the Nevi'im's rebuke, and the decree will be nullified and He will not bring the evil. I do evil to you in order that "Hikon Likras Elokecha Yisrael" (refer to 4:12:3:5).
Why does it say "Ekev"?
Rashi: Because you hear from My Nevi'im what I will do to you.
Radak: Because I do all this in front of your eyes.
Malbim: Hashem wants to benefit you. Your evil deeds force Him to do evil to you. You will be punished also for making Him do unlike He wanted ? the reward of an Aveirah is an Aveirah (Avos 4:2).
What do we learn from "Hikon Likras Elokecha Yisrael"?
Brachos 23a: If one feels a need to move his bowels, he may not pray.
Brachos 51b: One should not say Birkas ha'Mazon over a cup of wine if it will cause him to drink an even number of cups [in all] -- "Hikon Likros Elokecha Yisrael" (bless Him in a nice way), not with pairs. If via this cup, he drank an even number of cups, this brings problems.
Shabbos 10a: It is proper to pray with a belt. Rabah bar Rav Huna would put on nice socks before praying, due to our verse.
Rashi: Repent from your evil. Radak ? prepare to greet Him with Teshuvah and good deeds, and He will benefit you. He will reverse the evils for good, for He is Elokecha, and He oversees you for evil and good, based on your deeds. You are not like other nations!
Malbim: Put to your heart to greet Him, and appease Him with Teshuvah and good deeds. Do not wait until He comes to you and does the evil decreed against you!
