Some belated Torah on the parsha:
Among the brachos promised if we do the right thing is, “Y’kimcha Hashem lo l’am kadosh ka’asher nishba lach ki tishmor es mitzvos Hashem Elokecha v’halachta b’derachav” (28:9) – Hashem will sustain us as a holy people on the condition that we observe the mitzvos and "walk in His ways". The Netzi”v (and many others) asks: the list of brachos is prefaced in the very first pasuk of the chapter with the condition that they would be fulfilled only if we observe Hashem’s mitzvos, "V'haya im shamo'a..."; why is that condition repeated here again in pasuk 9 in the context of the bracha of "y'kimcha lo l'am kadosh"?
The key to understanding the pasuk lies in the words, “v’halachta b’derachav”, which Chazal interpret to mean that a person’s behavior should conform to the model of gemilus chessed demonstrated by Hashem, e.g. Hashem visited Avraham to heal the sick, Hashem helped bury the dead, etc., and therefore we should visit the sick, help bury the dead, and do other acts of chessed. A person may rightfully object that the social interaction that these mitzvos demands carries with it a price. A person who sits secluded in the Bais Medrash in private contemplation, locked in the ivory-tower of Torah, can rise to great heights of holiness and dveikus. However, once a person steps foot into the public domain, inevitably there is a hashpa’ah that the outside world has on a person’s dveikus and intensity.
Our pasuk answers that ta'anah. “Ki tishmor…v’halachta b’derachav” is not a condition – it’s a promise; not “if you observe… you will be holy”, but “when you observe… you will be holy”. Even though the observance of “v’halachta b’derachav” entails sacrificing the ivory tower of Torah, if done properly Hashem guarantees that “y’kimcha Hashem l’am kadosh”.