http://revach.net/article.php?id=3758

Section: Parshas HaShavua   Category: Mashal
Parshas Bichukosai: Rav Levi Yitzchok of Berditchev - Don't Forget What Kind Of Shidduch You Made
At the end of the Tochacha it says (Bichukosai 26:45), "V'Zacharti Lahem Bris Rishonim Asher Hotzaisi Oisum MeiEretz Mitzrayim."  After all the punishments, Hashem will remember the covenant he made with our forefathers whom he took out of Mitzrayim.

Rav Levi Yitzchok of Berditchev, in the Kedushas Levi, explains this with a Mashal.  When a person makes a Shidduch with someone based on the assumption that he is wealthy, if afterwards he discovers that the Mechutan does not have any money, he can rightfully be upset about being fooled.  But if he knew all along that his Mechutan was a man of limited means he cannot complain.

The tochacha is Hashem's response to our veering from the right path.  We made a Shidduch with Hashem and didn't keep our end of the deal.  But then Hashem brings up the memory of how it all started.  It started in Mitzrayim when we were very far removed from the path of Hashem, and even so, Hashem redeemed us and made us His chosen nation.  If so, when we do not serve Him as we should, Hashem cannot complain that we fooled Him.  With this memory, the curses of the Tochacha will end, and we will once again be taken into the loving arms of Hashem our Savior, Bimheira BiYameinu Amein!