In this week's parasha we read something really quite shocking: Isaac has become old (senile?), his eyes have become dim (perhaps with cataract?), and as a result he wishes to bless his older son Esau - a man whose values are far removed from those of his father Isaac and grandfather Abraham. 

The obvious implication is that because Isaac has become old, senile and blind, he really doesn't know what he is doing. But hold on! Firstly, we are not talking about just any "old geyser" - this is our holy forefather Isaac! Secondly, what value could there be in the blessing of someone who is so past it that he doesn't know what he's doing?

Rashi therefore explains that he became blind because of the incense that his daughters-in-law burnt to honour their idols. This is no ordinary blindness, says Rashi. This is a spiritual malaise brought about his proximity to idol-worshippers. 

Rashi is telling us that in spite of Isaac's greatness - he was affected by his environment. When  you live in a spiritually negative environment, no matter how holy you are, it is impossible for your judgement to remain unaffected. That is why he wished to invoke blessings on Esau instead of on the more spiritually deserving Jacob.

Indeed, Ramban says the same thing when discussing Abraham's spiritual decline upon approaching Egypt. 

If even these spiritual giants are so affected - what can we possibly say? We may not always be able to extricate ourselves from a spiritually negative environment - but we should at least be cognisant of its effects on our thinking. If we begin seeing things differently it may not be because we have "matured" or "grown". It may simply be the effects of our environment subtly pulling the needle of our moral compass.

~ RBZ Shabbat Toldos 5775