והיה עקב תשמעון את המשפטים האלה ושמרתם ועשיתם אתם ושמר ה' אלקיך לך את הברית (ז-יב)
The Rishonim offer a number of peirushim to explain the word "עקב". In truth, it would have sufficed to say "והיה תשמעון" - if you will adhere to the Torah. The word "עקב" seems to be superfluous and also an unusual choice of a word. (see Ramban)
Rashi explains that the Torah is promising us that if Klal Yisroel will be scrupulous in performing mitzvos and keeping the ways of the Torah, even those mitzvos which are commonly “stepped on with the heel” (because we mistakenly perceive them to be of lesser importance), then we will indeed be worthy of receiving this abundance of goodness.
Perhaps we can offer another two machshavos to understand this concept. Chazal say that the word "והיה" reflects simcha, happiness. A prerequisite to our entire avodas Hashem is to be b’simcha - in true bliss and tranquility, with a recognition that we, Am Yisroel, is privileged to serve Him day in and day out. So much so, that we will display a bounce in our step, in our “eikev”. Then, Hashem will shower us with beracha. Additionally, when we find ourselves in the confines of a shul or Beis Medrash, it is easier to serve Hashem correctly. The test is when we leave the heilige, protective environment of those mekomos hakedoshim. Says the posuk, “If, when you leave the sanctuaries and walk on your eikev, your heels, you are still a shomer Torah and mitzvos, then you are deserving of all the good Hashem has promised.”
I saw an additional pshat which is truly a timely lesson for us all. "והיה" - Hashem will be happy, "עקב" - even in the zman of “Ikvisa D’Moshicha” (the fearsome days before Moshiach), if we are "תשמעון" - still vigilant and withstanding the incredible nisyonos we are faced with. May we fulfill all these pshatim and be zoche that this zman of Ikvisa D’Moshicha be the time that we all see the kiyum of the Navi, כי נחם ה' ציון נחם כל חרבתיה .... ששון ושמחה ימצא בה תודה וקול זמרה - Amen!